Joezy-Shekalgorabi, Sahereh, Abdol Ahad Shadparvar, Albert De Vries, and Keegan Douglas Gay. 2014. “The Extent of Increase in First Calving Age As a Result of Implementing Various Sexed Semen Breeding Strategies”. Spanish Journal of Agricultural Research 12 (1), 106-16. https://doi.org/10.5424/sjar/2014121-4516.