Bulgarian Institute of Solid State Physics
Bulgarian Academy of Sciences
English

Home

Physicists

Funds

Donors

Exhibitions

Symposium

Jubilee

News

Video

References

Links

Services

Bookstore

Union of the Physicists in Bulgaria
Memoirs

Created 7.2.2018
Updated 24.1.2024
Protocols
Records
Sertificates
Biography
Alexander Georgiev Petrov
Emeritus Prof., Sc.D., Fellow of BAS

Born in Stara Zagora (27.05.1948)

Education

  1. (1987) DSc in Physics from Bulgarian Academy of Sciences, Sofia. DSc Thesis: Molecular Physics and Biophysical Aspects of Lyotropic Liquid Crystalline State of Matter

  2. (1974) PhD in Physics from Bulgarian Academy of Sciences, Sofia. PhD Thesis: Electric Polarization of Nematic Liquid Crystals: Dielectric and Flexoelectric Properties

  3. (1966 – 1970) MSc in Atomic Physics from St. Kliment Ochridski University of Sofia. Master Thesis: Dielectric Properties of Nematic Liquid Crystals with Ellipsoidal Molecules

Professional Experience

  1. (2006–2015) Head of Soft Matter Division, ISSP-BAS

  2. (2003) Fellow of the Bulgarian Academy of Sciences

  3. (1999–2015) Director, Institute of Solid State Physics-BAS

  4. (1991–2008) Head of Biomolecular Layers Department, ISSP-BAS

  5. (1990–2017) Professor, ISSP-BAS

  6. (1984–1990) Associate Professor, ISSP-BAS

  7. (1974–1989) Scientific Secretary of Sofia Liquid Crystal Group

  8. (1974–1984) Assistant Professor, ISSP-BAS

  9. (1971–1974) Research Scientist, Liquid Crystal Department, Institute of Solid State Physics (ISSP), Bulgarian Academy of Sciences (BAS), Sofia

Research
    Area: Liquid crystal physics, membrane biophysics and biomolecular electronics: Six new effects in liquid crystal physics and in living matter physics are discovered experimentally and interpreted theoretically, notably bioflexoelectricity and biohelielectricity. These new effects are applied in optoelectronics, nanotechnology, membrane biophysics. Holder of five patents on liquid crystal display devices

    Guest-Lecturer

    1. (2008, 2010, 2013) Visiting Professor, Centre for Liquid Crystal Research, Bangalore

    2. (2008) Invited Professor, Liquid Crystal Institute, Kent, Ohio

    3. (2004, 2006) Invited Professor, Universita della Calabria

    4. (2003) Visiting Professor, SUNY Buffalo

    5. (2002) JSPS Fellowship, Japan

    6. (2001) NATO Expert Visitor, SUNY Buffalo

    7. (1999-2001) Bulgarian Principal Investigator, NATO Linkage Grant with Nottingham University

    8. (1997) Visiting Scholar, Leipzig University

    9. (1996-1997) Bulgarian Principal Investigator, Royal Society Collaborative Grant with Nottingham University

    10. (1994-1996) Bulgarian Principal Investigator, NATO Collaborative Research Grant with Sheffield Hallam University

    11. (1994) Invited Professor, Universita della Calabria

    12. (1994) EC Senior Go West Grantee, Nottingham University

    13. (1993) NSF Visiting Scholar, Syracuse University, USA

    14. (1993) Invited Professor, Universite de Paris-Sud, Orsay

    15. (1991-1996) Bulgarian Principal Investigator, British Council Academic Link with Nottingham University

    16. (1989-1990) SERC Senior Research Fellow, Nottingham University

    17. (1988) Guest-Professor, Technical University, Munich

    18. (1980) Leipzig University

    Administrative Experience:

    1. (2015) Honorary Member of ISSP-BAS

    2. (2015) President, Union of the Physicists in Bulgaria (2010 - 2017). President, Balkan Physical Union

    3. (2009) Chairman of the Natural and Mathematical Sciences Division of the Fellows of BAS’ Assembly

    4. (2009-2015) Chairman of the Consultative Council on Nanosciences, new materials and technologies at the Administrative Council of BAS

    5. (2005) 1st Award for a Completed Project of the Ministry of Education and Science of Bulgaria

    6. (2003-2010) Chairman of the Specialized Scientific Council on Condensed Matter Physics at the Higher Attestation Commission of the Republic of Bulgaria

    7. (2003) Fellow of the World Innovation Foundation

    8. (2002) Member, Editorial Council of the journal Zhidkie Kristalli, Ivanovo

    9. (2001 and 2003) Co-organizer of the 1st and 2nd World Congress on Bioflexoelectricity, Buffalo and Houston

    10. (2000) President, Bulgarian Liquid Crystal Society

    11. (2000) Member, Intern. Adv. Board, Lyotropic Liquid Crystal Conference, Ivanovo

    12. (1998) Member, Research Board of Advisors, The American Biographical Institute

    13. (1995-2000) Member of the Editorial Board, Europhysics News

    14. (1995-1999) Chairman of the Scientific Council, ISSP-BAS

    15. (1995-2001, 2007-2010) Vice President, Union of the Physicists of Bulgaria

    16. (1994-1997) Member of the Higher Attestation Commission of the Republic of Bulgaria

    17. (1993) Member of the International Advisory Committee; 2nd Liquid Matter Conference of EPS; Firenze

    18. (1992) Member of the Administrative Council, Union of the Physicists of Bulgaria

    19. (1991) Advisory Editor, European Biophysics Journal

    20. (1989-1999) Member of the International Advisory Board of the European Liquid Crystal Conferences

    21. (1987) Guest-Editor, Molecular Crystals and Liquid Crystals

    22. (1987) Vice-Chairman, 5th European Liquid Crystal Conference, Borovets, Bulgaria

    23. (1984) Scientific Secretary, International School-Colloquium "Lyotropics and Biomembranes", Varna, Bulgaria

    24. (1977) Scientific Secretary, 2nd Liquid Crystal Conference of E.European Countries, Sunny Beach, Bulgaria

    Awards

    1. (10 May 2018) „St. Kyril and Methodius“ state medal – necklace

    2. (2008) Marin Drinov sign of honour of BAS on a ribbon

    3. (2007) Annual Award of the Ministry of Education and Science of Bulgaria for outstanding contribution to science

    4. (2004) Freedericksz medal of the Russian Liquid Crystal Society for outstanding achievements in liquid crystal physics.

    5. (2000) Biennial award in Physics, Bulgarian Academy of Sciences

    6. (1999) Award, National Council “Scientific Studies”, Ministry of Education and Science of Bulgaria

    International Recognitions

    1. (2012) Flexoelectricity in Liquid Crystals. Theory, Experiments and Applications. Chapter 6. Imperial College Press, London

    2. (2007) Current Topics in Membranes, vol. 58: Mechanosensitive channels, Elsevier/Academic Press

    3. (2006) Analytica Chimica Acta, Elsevier

    4. (2003) Invited book chapters in “Planar Lipid Bilayers (BLMs) and their Applications”, Elsevier Science

    5. (2002) BBA-Biomembranes, Elsevier

    6. (2001) EMIS Datareviews Series

    7. (1994) European Biophysics Journal, Springer

    8. (1984) Monographic review in Progress of Surface Science

    9. (1983) Invited reviews in Mendeleev Journal of All-Union Chemical Society

    Publications

    1. (2017) A. Ayriyan, E. Ayrjan, A. Egorov, M. Dencheva-Zarkova, G. Hadjichristov, Y. Marinov, I. Maslyanitsyn, A. G. Petrov, L. Popova, V. Shigorin, A. Strigazzi, S. Torgova, Modeling of static electric field effecton nematic liquid crystal director orientation in side-electrode cell, Mathematical Modeling and Computational Physics: Book of Abstr. of the Intern. Conf. (3–7 July 2017) Dubna, JINR

    2. (2017) G. Hadjichristov, Y. Marinov, A. G. Petrov, S. Prasad, Photoresponsive azo-doped aerosil/7CB nematic nanocomposites: the effect from concentration of the azobenzene photoactive agent, J. Phys: Conf. Series 794, 012037

    3. (2017) Y. Marinov, M. Marinov, G. Hadjichristov, A. G. Petrov, S. Prasad, L. Marino, N. Scaramuzza, Dielectric study of azo-doped aerosil/7CB nematic nanocomposite upon UV light, Journal of Physics: Conf. Series 780, 012009

    4. (2017) Y. Marinov, G. Hadjichristov, A. G. Petrov, H. Koduru, L. Marino, N. Scaramuzza, Dielectric and electrical behaviours of polymeric (PEO/PVP):NaIO4 composite for solid electrolytes, IOP Conf. Series: Journal of Physics: Conf. Series 794, 012020

    5. (2017) H. Koduru, L. Marino, F. Scarpelli, A. G. Petrov, Y. Marinov, G. Hadjichristov, M. Iliev, N. Scaramuzza, Structural and dielectric properties of NaIO4 Complexed PEO/PVP blended solid polymer electrolytes, Current Applied Physics, 17, 1518-1531

    6. (2016) A. Ayriyan, E. Ayrjan, A. Egorov, G. Hadjichristov, Y. Marinov, I. Maslyanitsyn, A. G. Petrov, J. Pribis, L. Popova, V. Shigorin, A. Strigazzi, S. Torgova, Some Features of Second Harmonic Generationin the Nematic Liquid Crystal 5CBin the Pulsed-Periodic Electric Field, Physics of Wave Phenomena, 24, No. 4, pp. 1–9

    7. (2016) G. Hadjichristov, Y. Marinov, A. G. Petrov, Electrically and spatially controllable PDLC phase gratings for diffraction and modulation of laser beams, Am.Inst.Phys. Conf.Proc. 1722, 290007 (1-4)

    8. (2016) Y. Marinov, G. Hadjichristov, A.G. Petrov, S. Krishna Prasad, Photo-controllable electro-optics of aerosil/7CB nanocomposite nematic doped with azo-bonded molecules, Journal of Physics: Conference series, 682, 012030

    9. (2016) G. Hadjichristov, Y. Marinov, A. G. Petrov, L. Marino, N, Scaramuzza, Dielectric and electrical characterization of 5CB nematic liquid crystal doped with silver nanoparticles, Journal of Physics: Conference Series 682, 012015

    10. (2016) Y. Marinov, G. Hadjihristov, A. G. Petrov, S. Krishna Prasad, Electro-optic modulation by silica-nanostructured nematic system (aerosil/7CB nanocomposite), Composites Part B90,471–477

    11. (2014) A. G. Petrov, Living Matter Physics, Marin Drinov Academic Edition, Sofia

    12. (2007) A. G. Petrov, Lyotropic State of Matter, Taylor and Francis

    13. (2002) A. G. Petrov, F. Sachs, Flexoelectricity and elasticity of asymmetric biomembranes. Physical Review E (65) 021905-10 (2002)

    14. (1999) A. G. Petrov, The Lyotropic State of Matter. Molecular Physics and Living Matter Physics, Gordon & Breach Publ, New York

    15. (1999) A. G. Petrov, Liquid Crystal Physics and the Physics of Living Matter, Molecular Crystals and Liquid Crystals, 332 (1) 577-584 (1999)

    16. (1996) A. G. Petrov, M. Spassova, J. Fendler, Flexoelectricity and photoflexoelectricity in model and biomembranes, Thin Solid Films, 284-285, 845-848 (1996)

    17. (1994) A. Todorov A. G. Petrov, J. Fendler, Flexoelectricity of charged and dipolar bilayer lipid membranes studied by stroboscopic interferometry. Langmuir (10) 2344-2350 (1994)

    18. (1993) A. G. Petrov, B. Miller, K. Hristova, P. Usherwood, Flexoelectric effects in model and native membranes containing ion channels, European Biophysics Journal (22) 289-300 (1993)

    19. (1992) G. Ivanov, K. Kostadinov, A. G. Petrov, Aspects of Langmuir-Blodgett trough design: computerization, surface pressure measurement, unevenness of motion, generated vibrations, Thin Solid Films (210) 13-15 (1992)

    20. (1987) A. G. Petrov, A. Derzhanski, Generalized asymmetry of thermotropic and lyotropic mesogens, Mol. Cryst. Liq. Cryst. 151, 303

    21. (1986) A. G. Petrov, V. S. Sokolov, Curvature electric effect in black lipid membranes, Eur. Biophys. J. 13, 139

    22. (1986) A. G. Petrov, L. Mircevova, Is flexoelectricity the coupling factor between chemical energy and osmotic work in the pump? A model of pump, Gen. Physiol. Biophys. 5, 391

    23. (1986) A. Derzhanski, A. G. Petrov, M. D. Mitov, Future development of the multipole model of molecular asymmetry in thermotropics and lyotropics. Dependence of the generalized multipoles on the generalized fields, Wiss. Beitrage MLU Halle 52, 170

    24. (1986) A. G. Petrov, L. Mirchevova, Is flexoelectricity the coupling factor between chemical energy and osmotic work in the pump? A model of pump. General Physiology and Biophysics (5) AEPress (1986)

    25. (1986) A. G. Petrov, Molecular physics and biophysical aspects of lyotropic liquid crystal state of matter (in Bulgarian), D.Sc. Thesis, Inst Solid State Physics, Bulg Acad Sci, Sofia, 507 pp.

    26. (1984) A. G. Petrov, Flexoelectricity of lyotropics and biomembranes, Nuovo Cimento 3D, 174

    27. (1984) A. G. Petrov, M. M. Kozlov, Curvature elasticity and passage formation in lipid bilayers. Lattice of passages, Compt. rend. Acad. bulg. Sci. 37, 1191

    28. (1984) V. F. Pastushenko, A. G. Petrov, Electromechanical mechanism of pore formation in bilayer lipid membranes, Seventh School Biophys. Membrane Transport, Poland 1984, Proceedings, vol. II, pp 69-91 Wroclaw

    29. (1984) A. G. Petrov, I. Bivas, Elastic and flexoelectric aspects of out of plane fluctuations in biological and model membranes, Progress in Surface Sci., Ed. S. Davison, 16, 389 512

    30. (1983)L. Komitov, A. G. Petrov, Optical method for determination of anchoring energy of tilted nematic layers, phys. stat. sol.(a) 76, 137

    31. (1983) A. Hauser, G. Pelzl, C. Selbmann, D. Demus, S. Grande, A. Petrov, Order parameter and molecular polarizabilities of liquid crystals with nematic and smectic phases, Mol. Cryst. Liq. Cryst. 91, 97

    32. (1983) K. Gawrisch, M. Mitov, A. Mops, A. G. Petrov, Bestimmung der Phasenubergangstemperaturen lyotroper flussig-crystalliner, Systeme mittels Microscopie im polarisierten Licht, Wiss. Ber. Karl Marx Universitat Leipzig, 32, 80

    33. (1983) L. Komitov, A. G. Petrov, Quasihomeotropic, reversely pretilted hematic liquid crystal layers. Electrooptical behaviour, phys. stat. sol. (a) 79, 623

    34. (1983) L. Komitov, A. G. Petrov, A novel polar electrooptic effect in reversely pretilted nematic liquid crystal layers with weak anchoring, Japan Display '83: Proc. 3rd Int. Display Res. Conf. Kobe, p. 482

    35. (1983) S. A. Seleznev, A. G. Petrov, Short and long range interactions of proteins and mesomorphic lipids within biological membranes, Compt. rend. Acad. bulg. Sci. 36, 615-618

    36. (1983) A. G. Petrov, G. Durand, Thermal instability in lamellar phases of lecithin: a planar undulation model, J. Physique Lett. 44, L 793

    37. (1982) K.Gawrisch, K. Arnold, A. G. Petrov, G. Brezesinski, A.Mops, A.Losche, G. Klose Optical, DSC and 31P NMR investigations of phase separation in phosphatidylcholine/phosphatidylethanolamine mixtures, studia biophysica, 90, 131

    38. (1982) A. G. Petrov, K. Gawrisch, G. Brezesinki, G. Klose, A. Mops, Optical detection of phase transitions in simple and mixed lipid water systems, Biochim. Biophys. Acta 690, 1

    39. (1982) A. G. Petrov, M. D. Mitov, Defects in lipid bilayers and their influence on membrane fusion, Studia biophysica 90, 223

    40. (1982) G. Klose, A. G. Petrov, F. Volke, H. Meyer, G. Forster, W. Rettig, Self assembly and phase behaviour of short chain phosphonic acid water systems in a wide concentration range. Microscopic, NMR and X ray diffraction studies, Mol. Cryst. Liq. Cryst. 88, 109

    41. (1982) A. Derzhanski, A. G. Petrov, Multipole model of the molecular asymmetry in thermotropic and lyotropic liquid crystals. Volume and surface effects, Mol. Cryst. Liq. Cryst. 89, 339

    42. (1981) A. Derzhanski, A. G. Petrov, Y. V. Pavloff, Curvature induced conductive and displacement currents through lipid bilayers, J. Physique Lett. 42, L 119

    43. (1981) I. Bivas, A. G. Petrov, Flexoelectric and steric interactions between two lipid bilayer membranes resulting from their curvature fluctuations, J. theor. Biol. 88, 459-483

    44. (1981) A. G. Petrov, The problem of self assembly of lipids and proteins into liquid crystalline membrane structures, Sixth School Biophys. Membrane Transport, Poland, Proceedings, vol. 1, p. 116

    45. (1981) A. G. Petrov, H. Frischleder, On the theory of domain formation in mixed lipid systems, Chem. Phys. Lipids, 29, 165

    46. (1981) I. Gorina, N. Sizova, I. Chistyakov, A. G. Petrov, A. Derzhanski, The observation of hydrodynamic instability in a cholesteric liquid crystal having a free surface, Mol. Cryst. Liq. Cryst. 66, 159

    47. (1980) N. Aneva, A. G. Petrov, S. Sokerov, S. Stoylov, Dynamics of the Freedericksz transition in the electric field in non ideally oriented nematic layers at subthreshold and above threshold voltages, Mol. Cryst. Liq. Cryst. 60, 1

    48. (1980) A. G. Petrov, S. Naydenova, Stabilization of foam films of nonionic detergents by liquid crystals, J. Disp. Sci. Technol. 1, 283

    49. (1980) A. Derzhanski, A. G. Petrov, I. Bivas, Molecular asymmetry, flexoelectricity and elasticity of nematics, Advances in Liq. Cryst. Res. and Appl., Ed. L. Bata, Pergamon Press, Oxford Akad. Kiado, Budapest, vol. 1, p. 505

    50. (1980)A. Derzhanski, A. G. Petrov, Gradient flexoelectric effect and longitudinal domains in nematics, Advances in Liq. Cryst. Res. and Appl., Ed. L. Bata, Pergamon Press, Oxford Akad. Kiado, Budapest, vol. 1, p. 515

    51. (1980) A. G. Petrov, M. Mitov, A. Derzhanski, Edge energy and pore stability in bilayer lipid membranes, Advances in Liq. Cryst. Res. and Appl., Ed. L. Bata, Pergamon Press, Oxford Akad. Kiado, Budapest, vol. 2, p. 695

    52. (1980) L. Vistin', A. G. Petrov, N. Shonova, A. Derzhanski, Generation of low frequency electrical and optical oscillations in a system liquid crystal cell solar cell, Advances in Liq. Cryst. Res. and Appl., Ed. L. Bata, Pergamon Press, Oxford Akad. Kiado, Budapest, vol.2, p. 1213

    53. (1979) A. G. Petrov, Electrohydrodynamic instability in planar, positive dielectric anisotropy nematic layers at d.c. excitation, J. Physique suppl. 40, C3 310

    54. (1979) A. G. Petrov, Y. Pavloff, A new model for flexoelectric polarization of bilayer lipid membranes at blocked "flip flop", J. Physique suppl. 40, C3 455

    55. (1979) A. G. Petrov, S. Seleznev, A. Derzhanski, Principles and methods of liquid crystal physics applied to the structure and functions of biological membranes, Acta. Phys. Polonica A55, 385 405

    56. (1979) A. Derzhanski, A. G. Petrov, Flexoelectricity in nematic liquid crystals, Acta Phys. Polonica A55, 747

    57. (1979) A. G. Petrov, The biomembrane as a liquid crystalline system, Fifth Winter School Biophysics, Membrane Transport, Poland, Proceedings vol. 1, p. 297

    58. (1979) M. Mitov, A. G. Petrov, A. Derzhanski, Edge energy and pore stability in membranes molecular description, Fifth Winter School Biophysics, Membrane Transport, Poland, Proceedings, vol. 2, p. 313

    59. (1979) A. Derzhanski, A. G. Petrov, M. Mitov, Electric field induced pores in erythrocyte membranes a discussion, Fifth Winter School Biophysics, Membrane Transport, Poland, Proceedings, vol. 2, p. 285

    60. (1979) M. Mitov, A. G. Petrov, A new interpretation of the experiments on osmotic pressure induced pores in phospholipid vesicles, Proc. Colloques nationaux du C.N.R.S. No 938 Physicochimie des composes amphiphiles, p. 249

    61. (1978) A. G. Petrov, V. Tverdislov, A. Derzhanski, Flexoelectric aspects of lipid protein interaction in biomembranes, Ann. Phys. 3, 273. 4

    62. (1978) A. Derzhanski, A. G. Petrov, M. Mitov, Molecular asymmetry and saddle splay elasticity in lipid bilayers, Ann. Phys. 3, 297

    63. (1978) A. G. Petrov, M. Mitov, A. Derzhanski, Saddle splay instability in lipid bilayers, Phys. Lett. 65A, 374

    64. (1978) A. Derzhanski, A. G. Petrov, M. Mitov, One dimensional dielectric flexoelectric deformations in nematic layers, J. Physique 39, 273

    65. (1978) A. G. Petrov, Mechanisms of curvature induced membrane polarization and their influence on some membrane properties, studia biophysica 74, 51, and Microphiche 4/ 14 25

    66. (1977) A. G. Petrov, Flexoelectric effects and transport phenomena in biomembranes, Fourth Winter School Biophys. Membrane Transport, Poland School Proceeding, vol. 3, p. 168 176

    67. (1977) A. G. Petrov, A. Derzhanski, Flexoelectricity and surface polarization, Mol. Cryst. Liq. Cryst. Lett. 41, 41

    68. (1976) S. Sokerov, N. Aneva, P. Stefanov, A. G. Petrov, S. Stoylov, V. Encheva, Electrooptic study of nematic liquid crystal ZLI 207 (in Bulgarian), Izv. Khimia (Sofia) 9, 304

    69. (1976) A. G. Petrov, A. Derzhanski, On some problems in the theory of elastic and flexoelectric effects in bilayer lipid membranes and biomembranes, J. Physique suppl. 37, C3 155 – C3-160

    70. (1975) A. Derzhanski, A. G. Petrov, I. Bivas, One dimensional approach to the spontaneous deformations in nematic liquid crystals, Compt. rend. Acad. bulg. Sci. 28, 1327

    71. (1975) A. G. Petrov, Flexoelectric model for active transport, In: Physical and Chemical Bases of Biological Information Transfer, Plenum Press, N. Y. L. p. 111.

    72. (1974) A. Derzhanski, A. G. Petrov, Chr. Khinov, B. L. Markovski, Piezoelectric deformations of nematic liquid cristals in nonhomogeneous d.c. electric field, Bulg. J. Phys. 1, 165

    73. (1974) A. G. Petrov, Electric polarization of nematic liquid crystals dielectric and piezoelectric properties (in Bulgarian), Ph.D.Thesis, Institute of Solid State Physics, Bulgarian Academy of Sciences, Sofia

    74. (1972) A. Derzhanski, A. G. Petrov, A molecular statistical approach to the piezoelectric properties of nematic liquid crystals one dimensional model, Compt. rend. Acad. bulg. Sci. 25, 167

    75. (1971) A. Derzhanski, A. G. Petrov, Dielectric properties of nematic liquid crystal with ellipsoidal molecules, Compt. rend. Acad. bulg. Sci. 24, 569

    76. (1971) A. G. Petrov, Molecular parameters and dielectric anisotropy of liquid crystal p-azoxyanisole, Compt. rend. Acad. bulg. Sci. 24, 573

    77. (1971) A. Derzhanski, A. G. Petrov, A possible relationship between the dielectric permeability and the piezoelectric properties of nematic liquid crystals, Phys. Lett. 34A, 427

    78. (1971) A. Derzhanski, A. G. Petrov, Inverse currents and contact behaviour of some nematic liquid crystals, Phys. Lett. 36A, 307

    79. (1971) A. Derzhanski, A. G. Petrov, A molecular statistical approach to the piezoelectric properties of nematic liquid crystals, Phys. Lett. 36A, 483

    80. (1971) A. Derzhanski, S. Naydenova, L. Grigorov, A. G. Petrov, NMR Fourier spectroscopy in liquid crystals, Proc. XVIth Congress AMPERE, Bucharest, p.841

    References:

    1. Who is Who in the World

    2. 2000 Outstanding Scientists of 20th Century

    3. A. G. Petrov

    Back

    Web