Y. Yunilas, L. Warly, Y. Marlida, and I. Riyanto, “Quality Improvement of Oil Palm Waste-Based Feed Product Through Indigenous Microbial Fermentation to Reach Sustainable Agriculture”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 4, no. 4, pp. 282–285, Aug. 2014.