Febrina, Dewi, et al. “The Effects of P, S and Mg Supplementation of Oil Palm Fronds Fermented by Phanerochaete Chrysosporium on Rumen Fluid Characteristics and Microbial Protein Synthesis”. Pakistan Journal of Nutrition, vol. 15, no. 3, Feb. 2016, pp. 299–304, https://doi.org/10.3923/pjn.2016.299.304.