K.N. MEENA, et al. “Productivity and Nutrient Uptake of Maize (Zea mays)wheat (Triticum Aestivum) Cropping System under Different Bio-Sources and Nitrogen Levels”. Indian Journal of Agronomy, vol. 56, no. 3, Oct. 2001, pp. 182-8, https://doi.org/10.59797/ija.v56i3.4692.