Sawana, Z.M., Hafez, S.A. and Alkassas, A.R. 2007. Nitrogen, potassium and plant growth retardant effects on oil content and quality of cotton seed. Grasas y Aceites. 58, 3 (Sep. 2007), 243–251. DOI:https://doi.org/10.3989/gya.2007.v58.i3.179.