References
- Harvey, W.R. (1960) United States Department of Agriculture, ARS-20-8, 157pp
- Working Group 3 (1981) World's Poultry Science Journal 37: 218–221.
- Working Group 3 (1984) World's Poultry Science Journal 40: 86–87.
- Working Group 3 (1986) World's Poultry Science Journal 42: 276–284.
- Working Group 3 (1989) World's Poultry Science Journal 45: 189–192.
- Working Group 3 (1992) World's Poultry Science Journal 48: 269–270.