2. Steroids and related studies. Part XVIII. 3-Aza-A-homo-4a-eno[3,4-d]tetrazole steroid analogues Harkishan Singh,R. B. Mathur,P. P. Sharma J. Chem. Soc. Perkin Trans. 1 1972 990
3. Steroids and related studies. Part XXVII. Tetrazoles from progesterone and 7-oxocholest-5-en-3β-yl acetate Harkishan Singh,Ravinder K. Malhotra,N. K. Luhadiya J. Chem. Soc. Perkin Trans. 1 1974 1480