1. Dosaggio del progesterone e sue pratiche applicazioni in campo zootecnico. Nota II: diagnosi di gravidanza precoce;Beghelli,1977
2. Applications of ultrasonography in reproduction in sheep and goats;Buckrell;Theriogenology,1988
3. Diagnostic de gestation et induction de la parturition;Calus;Revue de l'Agriculture,1987
4. Les méthodes de diagnostic de gestation applicables aux ovins et caprins;Jardon,1984
5. Early pregnancy diagnosis in ewes by determining the progesterone content of the blood plasma;Kasztelan;Anim. Breed. Abstr.,1986