Dung, B.V., Xuan, C.T., Hue, L.T. and Ty, L.V. 2012. Improvement of the results of artificial insemination by synchronization of estrus and ovulation for beef cattle treated with GnRH and PGF2. Academia Journal of Biology. 32, 3 (May 2012), 78–82. DOI:https://doi.org/10.15625/0866-7160/v32n3.711.