Abdulgabbar Ali, E., Zhandi, M., Towhidi, A., Zaghari, M., & Ansari, M. "The effect of dietary Letrozole on plasma gonadotropin concentrations and some testicular histology parameters in 40 weeks old broiler breeder rooster", Iranian Journal of animal Science, 48, 2, 2017, 175-183. doi: 10.22059/ijas.2017.231769.653523