Srivastava, S K, K L Sahni, Uma Shanker, P C Sanwal, and V P Varshney. 2012. “Seasonal Variation in Progesterone Concentration During Oestrus Cycle in Murrah Buffaloes”. The Indian Journal of Animal Sciences 69 (9). https://epubs.icar.org.in/index.php/IJAnS/article/view/21218.