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2. Veterinary Reproduction and Obstetrics;Arthur,1975
3. Causes of fertilization failure in repeat breeding cattle;Graden;J. Dairy Sci.,1968
4. A contribution to the etiology of delayed ovulation in the cow;Grünert;Dtsch. Tieraerztl. Wochenschr.,1976
5. Conception rates of repeat-breeder cows bred after progesterone and chorionic gonadotrophin treatment during estrus;Hansel;Cornell Vet.,1960