Shafey T, Ghannam M, Al-Batshan H, Al-Ayed M. Effect of Pigment Intensity and Region of Eggshell on the Spectral Transmission of Light That Passes the Eggshell of Chickens. Int. J. Poult. Sci. 2004;3(3):228–233. doi:10.3923/ijps.2004.228.233