Chen, H., F.F. Yan, J.Y. Hu, Yanan Wu, C.M. Tucker, A.R. Green, and H.W. Cheng. 2017. “Immune Response of Laying Hens Exposed to 30 Ppm Ammonia for 25 Weeks”. International Journal of Poultry Science 16 (4): 139–146. https://doi.org/10.3923/ijps.2017.139.146.