Campos, Jefferson Tadeu, et al. “Pregnancy Rate Evaluation in Lactating and Non-Lactating Nelore Cows Subjected to Fixed-Time Artificial Insemination Using Injectable Progesterone”. Semina: Ciências Agrárias, vol. 37, no. 4, Aug. 2016, pp. 1991-6, doi:10.5433/1679-0359.2016v37n4p1991.