Institution: | a Andronikashvili Institute of Physics, 6 Tamarashvili St., Tbilisi 0177, Georgia b Javakhishvili State University, 3 Chavchavadze Ave., Tbilisi 0128, Georgia c Ilia State University, 3/5 Kakutsa Cholokashvili Ave., Tbilisi 0162, Georgia d Gori University, 53 Chavchavadze St., Gori 1400, Georgia |