Parmar, V. S.; Sharma, Sunil; Rathore, J. S.; Garg, Meenu; Gupta, Sandhya; et al.
Magnetic Resonance in Chemistry, 1990 , vol. 28, # 5 p. 470 - 474

Pathak, V. P.; Khanna, R. N.
Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry, 1982 , vol. 21, # 9 p. 891 - 892