Trziszka, T.; Saleh, Y.; Kopeae, W.; Siewinski, M.; Wesierska, E. Effect of Hen`s Age on the Level of Cystatin in the Chicken Egg White. Int. J. Poult. Sci. 2004, 3 (7), 471–477. https://doi.org/10.3923/ijps.2004.471.477.