HayatiR. N., Panjono Panjono, and IrawanA. 2021. “Estrous Signs and Progesterone Profile of Ongole Grade Cows Synchronized at Different Ages Fed Different Level of Dietary Crude Protein”. Tropical Animal Science Journal 44 (1), 16-23. https://doi.org/10.5398/tasj.2021.44.1.16.