E. Urzúa González, L. Ángel Valdés Pérez, A. Garza, G. Mapes, C. G. Gutiérrez, and J. Hernández-Cerón, “Pregnancy rate in dairy cows treated with human chorionic gonadotropin five days after insemination”, Austral j vet sci, vol. 49, no. 2, pp. 119–122, Jun. 2017.