SHUKLA, A.K. (2011) “Nitrogen use efficiencies using leaf colour chart in rice (Oryza sativa)-wheat (Triticum aestivum) cropping system”, The Indian Journal of Agricultural Sciences, 76(11). Available at: https://epubs.icar.org.in/index.php/IJAgS/article/view/3259 (Accessed: 27 October 2025).