Akpan, H., Udosen, E., Udofia, A., Akpan, E., & Joshua, A. (2005). The Effect of Phytase and Zinc Supplementation on Palm Kernel Cake Toxicity in Sheep. Pakistan Journal of Nutrition, 4(3), 148-153. https://doi.org/10.3923/pjn.2005.148.153