Bulkaini, Bulkaini, et al. “Production Performance of Peking Ducks With Feeding of Fermented Yeast Culture Pineapple Peel (Saccharomyces Cereviceae)”. Jurnal Biologi Tropis, vol. 21, no. 3, Oct. 2021, pp. 1013-21, doi:10.29303/jbt.v21i3.3034.