R.K. BAJPAI, et al. “Productivity and Economics of Rice (Oryza Sativa L.) Wheat (Triticum Aestivum) Cropping System under Integrated Nutrient Supply Systems”. Indian Journal of Agronomy, vol. 47, no. 1, Oct. 2001, p. 47_1 , https://doi.org/10.59797/ija.v47i1.3110.