Puangkhum, Chudapun, et al. “Effect of Supplemental Multi-Enzymes in the Diet of Meat-Type Ducks on Production Performance, Carcass Yields and Gastrointestinal Morphology”. International Journal of Poultry Science, vol. 18, no. 12, Nov. 2019, pp. 648–655, https://doi.org/10.3923/ijps.2019.648.655.