P. K. Chhonkar

30th Dr. R.V. Tamhane Memorial Lecture

P. K. Chhonkar, 2003 .

Manual on Soil Plant and Water Analysis

B. S. Dwivedi, Dhyan Singh, P. K. Chhonkar, 2013 .

Significant research and development with reference to biofertilisers in Chhattisgarh.

M. Gupta, S. B. Gupta, M. Adil, 2000 .