El-Ashmouny, Amany A., et al. “Effect of Pre-Sowing Application of Nitrogen, Potassium and Sulfur and Its Relationship on Egyptian Cotton Productivity.” International Journal of Environment, Agriculture and Biotechnology, vol. 2, no. 5, 2017, pp. 2387–93. Crossref, https://doi.org/10.22161/ijeab/2.5.15.