1. Comparative absorption and transport of five common carotenoids in pre-ruminant calves;Bierer;J. Nutr.,1995
2. Why egg yolk is yellow;Blount;Trends Ecol. Evol.,2000
3. Handbook of the birds of the western palearctic;Cramp,1983
4. β-Carotene supplementation of laying hen diet;Damron;Br. Poult. Sci.,1984
5. Del Hoyo, J., Elliot, A., Sargatal, J. (eds), 1996. Handbook of the birds of the world, vol. 3. Hoatzin to Auks. Lynx Editions, Barcelona.