1. K. Ashok Rao, B. Rangamannar,Radiochem. Radioanal. Lett., 54 /1982/ 325.
2. N. Muralidhar, K. Ashok Rao, B. Rangamannar, V. R. Krishnan,Radiochem. Radioanal. Lett., 55 /1982/ 215.
3. K. Ashoak Rao, P. C. Reddy, B. Rangamannar,Radiochem. Radioanal. Lett., 56 /1982/ 149.
4. K. Ashok Rao, N. Muralidhar, B. Rangamannar,Radiochem. Radioanal. Lett., 57 /1982/ 349.
5. K. Ashok Rao, B. Rangamannar,Radiochim. Acta /in press/.