Chowdhury, T., G. Ayam, S. Gupta, G. Das, and M. Pradhan. “Internal Nutrient Supply Capacity of Vertisols for Rice in Chhattisgarh Agro-Climatic Conditions of India”. Bangladesh Journal of Agricultural Research, vol. 32, no. 4, Oct. 2008, pp. 501-7, https://banglajol.info/index.php/BJAR/article/view/1268.