SINGH, M K, et al. “Integrated Nutrient Energy Management for Sustainability in Maize (Zea Mays) - Wheat (Triticum Aestivum) Cropping System”. The Indian Journal of Agricultural Sciences, vol. 68, no. 12, Feb. 2013, https://epubs.icar.org.in/index.php/IJAgS/article/view/27834.