1. Miljöns inverkan på beteendet hos kalvar och ungdjur av mjölkkoras;Bäckström,1977
2. Sucking behaviour affects the post-prandial secretion of digestive hormones in the calf;De Passillé,1991
3. Does drinking milk stimulate sucking in young calves?;De Passillé;Appl. Anim. Behav. Sci.,1992
4. Behaviour and welfare of veal calves in relation to husbandry systems;De Wilt;Thesis from the Institute of Agricultural Engineering, Wageningen,1985