1. Bhagavantam, S. and Venkatarayudu, T.Theory of Groups and Its Applications to Physical Problems, Andhra University, Waltair, 1948.
2. Gross, E. F. ..Hydrogen Bonding, by Hadzi, Pergamon Press, 1959, p. 203.
3. Gupta, S. J. and Majumdar, A. K.J. In. Chem. Soc., 1941,18, 457.
4. Kanda, F. A. and King, A. J.Jour. Amer. Chem. Soc., 1957,73, 2315.
5. Krishnan, R. S. and Balasubramanian, K.Proc. Ind. Acad. Sci., 1958,47 A, 55; 1958,48 A, 138.