1. Early breeding of dairy heifers;Amir;J. Brit. Soc. Anim. Prod.,1967
2. Anonymous. 1966. (With L. H. Schultz and J. W. Hibbs) What about early breeding of heifers? Hoard's Dairyman, 111(10): 642. May 25.
3. Effects of various postpartum treatments upon the reproductive efficiency of dairy cows;Brown;J. Dairy Sci.,1959
4. Accelerated growth and early breeding studies with Holstein heifers;Gardner;J. Dairy Sci.,1966
5. Breeding heifers early;Hibbs;Sunbelt Dairyman,1966