RiyuskaA., KarjaN. W. K., and SetiadiA. “Efficacy of Leptin Supplementation on Nuclear Maturation and Fertilization Rate of Sheep Oocytes In Vitro”. Tropical Animal Science Journal, Vol. 42, no. 1, Mar. 2019, pp. 1-5, doi:10.5398/tasj.2019.42.1.1.