Setiyatwan , H. et al. 2018. Effect of Fermentation using Trichoderma harzianum and Saccharomyces cerevisiae on Crude Protein, Crude fibre and Zinc Content of Duckweed. International Journal of Poultry Science. 17, 12 (Nov. 2018), 605–609. DOI:https://doi.org/10.3923/ijps.2018.605.609.