CHANDRA, SUBHASH, et al. “Effect of Varying Fertilization on Yield of Rice (Oryza Sativa)-Wheat (Triticum, Aestivum) System and Soil Fertility Status”. The Indian Journal of Agricultural Sciences, vol. 71, no. 10, Apr. 2014, https://epubs.icar.org.in/index.php/IJAgS/article/view/40256.