McGruder B, Zhai W, Keralapurath M, Gerard P, Peebles E. Effects of in ovo Injection of Theophylline and Electrolyte Solutions on Hatchability and Growth of Broilers from Day 0 to Day 10 Post-Hatch. Int. J. Poult. Sci. 2011;10(12):927–932. doi:10.3923/ijps.2011.927.932