1. Pearl, R. and F. M. Surface. Data on Certain Factors Influencing the Fertility and Hatching of Eggs. Maine Agricultural Experiment Bulletin 168, Page 153.
2. Hays, F. A. and R. Sanborn. The Inheritance of Fertility and Hatchability in Poultry. Massachusetts Agricultural Experiment Station Technical Bulletin 6, Page 41.
3. The Duration of Spermatozoa After Fecundation in the Pullet and the Duck.;Chappellier;Compt. Rend. Assoc. France Adv. Sci.,1914
4. Kaupp, B. F. Fertility Experiments. Jour. Amer. Inst. and Invest., Poultry Husbandry 5. Page 53.
5. Payne, L. F. Vitality and Activity of Sperm Cells and Artificial Insemination of the Chicken. Okla. Sta. Cir. No. 30.