1. Crest and hernia in fowls due to single gene without dominance;Fisher;Science,1934
2. Dominance in poultry;Fisher;Philosophical Transactions of the Royal Society of London,1935
3. Genetics of the Fowl;Hutt,1949
4. Die Haube der Hühner und Enten. Ihre Ursache, Entstehung und Vererbung;Krautwald,1910
5. Levitan, B. (1978). Personal communication.