National Symposium on "Approach to Higher Productivity of Crops" Calcutta, India, Das Gupta, D. K., & Chattopadhyay, N. C. (1980). Higher productivity in agriculture: Proceedings of the National Symposium on "Approach to Higher Productivity of Crops" held at the Ramakrishna Mission Institute of Culture, Calcutta, during May 19-20, 1978. Oxford & IBH.
Lua i Stíl Chicago (17ú heag.)National Symposium on "Approach to Higher Productivity of Crops" Calcutta, India, Dilip Kumar Das Gupta, agus N. C. Chattopadhyay. Higher Productivity in Agriculture: Proceedings of the National Symposium on "Approach to Higher Productivity of Crops" Held at the Ramakrishna Mission Institute of Culture, Calcutta, During May 19-20, 1978. New Delhi: Oxford & IBH, 1980.
Lua MLA (8ú heag.)National Symposium on "Approach to Higher Productivity of Crops" Calcutta, India, et al. Higher Productivity in Agriculture: Proceedings of the National Symposium on "Approach to Higher Productivity of Crops" Held at the Ramakrishna Mission Institute of Culture, Calcutta, During May 19-20, 1978. Oxford & IBH, 1980.