References
- Harvey, W.R. (1960) United States Department of Agriculture, ARS-20-8, 157 pp
- 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