1. SAS User’s Guide;Barr,1979
2. Intermittent lighting of mature Leghorn hens;Bell;Poultry Sci.,1973
3. Lighting chicken laying hens with less light an energy crisis topic;Biellier;Missouri Poult. Ind. News,1974
4. Effect of ahemeral light-dark cycles on length of interval between ovipositions in chicken hens;Biellier;Proc. 5th World Conf. Anim. Prod., Tokyo, Japan.,1983
5. Cooper, J. B., and B. D. Barnett, 1974. Photoperiods for layers. Pages 423–424 in Proc. 15th World’s Poult. Congr., New Orleans, LA.