Mirnawati, Rizal Y, Marlida Y, Kompiang IP. The Role of Humic Acid in Palm Kernel Cake Fermented by Aspergillus niger for Poultry Ration. Pak. J. Nutr. [Internet]. 2010 Jan. 15 [cited 2025 Sep. 1];9(2):182–185. Available from: https://pjnonline.org/pjn/article/view/1148