VARAVIPOUR, M, et al. “Effect of Applied. Phosphorus, Sulphur and Zinc on Yield and Uptake Parameters of wheat(Triticum Aestivum) and Soybean (Glycine Max) Grown on a Loamy Sand”. The Indian Journal of Agricultural Sciences, vol. 69, no. 1, Jan. 2013, https://epubs.icar.org.in/index.php/IJAgS/article/view/26112.