Srivastava, A. K.; Singh, V. P.; Srivastava, P. K., Indian Journal of Chemistry, Section A: Inorganic, Physical, Theoretical and Analytical, 1987, vol. 26, # 6, p. 502 - 505
Srivastava, A. K.; Singh, V. P.; Srivastava, P. K., Indian Journal of Chemistry, Section A: Inorganic, Physical, Theoretical and Analytical, 1987, vol. 26, # 6, p. 502 - 505