Ahmed, Omar B., Usama T. Mahmoud, Manal A.M. Mahmoud, and Mohamed R. Fath El-Bab. 2016. “Histomorphological Changes Associated With Different Doses of Chinese Propolis in the Bursa of Fabricius of Chickens”. Journal of Advanced Veterinary Research 6 (1):1-6. https://advetresearch.com/index.php/AVR/article/view/31.