1. Agricultural Economic Research Institute, 2000. Farm results in agriculture. Agricultural Economics Research Institute, The Hague, the Netherlands (in Dutch). http://www.lei.dlo.nl/binternet/bul/.
2. Agricultural Information and Knowledge Centre and Research Station for Animal Husbandry, 1999. Quantitative information on livestock industry 1999–2000. Research Station for Animal Husbandry, Lelystad, The Netherlands (in Dutch).
3. Central Bureau for Livestock Feeding, 1998. Standards for nutritional requirements of livestock and nutritional value of feed stuffs, shortened Table 1998. Central Bureau for Livestock Feeding, Lelystad, The Netherlands (in Dutch).
4. CR-Delta/NRS Division, 1998. Annual Statistics. CR-Delta/NRS Division, Arnhem, The Netherlands (in Dutch).
5. Path model of individual-calf risk factors for calfhood morbidity and mortality in New York Holstein herds;Curtis;Prev. Vet. Med.,1988