1. Steifel, E.I., Prog. Inorg. Chem., 1977, vol. 22, p. 1.
2. Prabhakaran, C.P. and Nair, B.G., Transition Met. Chem., 1983, vol. 8, no. 3, p. 68.
3. Harikumaran Nair, M.L. and Sheela, A., Indian J. Chem., Sect. A: Inorg., Bio-inorg., Phys., Theor. Anal. Chem., 2008, vol. 47, p. 1787.
4. Harikumaran Nair, M.L. and Kumari Nisha, K.R., Asian J. Chem., 2007, vol. 19, no. 6, p. 4487.
5. Harikumaran Nair, M.L. and Siji, V.L., J. Indian Chem. Soc., 2009, vol. 86, p. 441.