Institution: | 1. Department of Physics, University of Gorakhpur, 273 001, Gorakhpur, India 2. Ioffe Physical-Technical Institute of the Academy of Sciences of the USSR, Leningrad, USSR 3. Institut für Theoretische Physik der Universit?t Frankfurt/Main Robert-Mayer-Str. 10, D 6000, Frankfurt/Main, FRG
|