1. Some observations on post parturient cows in four separate herds as related to expulsion of their fetal membranes;Boyd;Cornell Vet.,1948
2. Prevention of retained fetal membranes in cattle;Curtis;Vet. Rec.,1973
3. Retained fetal membranes – the effect on prolificacy of dairy cattle;Erb;J.A.V.M.A.,1958
4. Retained fetal membranes in cows;Guerreiro;J.A.V.M.A.,1959
5. Harvey, W. R. 1960. Least-squares analysis of data with unequal subclass frequencies. USDA, ARS 20.