SINGH, V K, et al. “Effect of Site-Specific Nutrient Management on Yield, Profit and Apparent Nutrient Balance under Pre-Dominant Cropping Systems of Upper Gangetic Plains”. The Indian Journal of Agricultural Sciences, vol. 85, no. 3, Mar. 2015, pp. 335-43, https://doi.org/10.56093/ijas.v85i3.47096.