Singh, Om V.; Khanna, Mahavir S.; Tanwar, Madan P.; Garg, Chandra P.; Kapoor, Ram P.
Synthetic Communications, 1990 , vol. 20, # 16 p. 2401 - 2408

Kumar; Singh
Synthetic Communications, 1992 , vol. 22, # 9 p. 1333 - 1337