YÁNEZ-AVALOS, D.; LÉPEZ PARRA, J.; MOYANO TAPIA, J.; QUINTEROS POZO, R.; MARINI, P. Fixed-time artificial insemination in beef cattle with prolonged proestrus of 60 and 72 hours. Agronomía Mesoamericana, v. 29, n. 2, p. 363-373, 1 maio 2018.