1. The milk-molars of Perissodactyla, with remarks on molar occlusion;Butler;Proc. Zool. Soc. Lond.,1952
2. The ontogeny of molar pattern;Butler;Biol. Rev.,1956
3. Butler , P. M. 1961 Relationships between upper and lower molar patterns. International Colloquium on the evolution of lower and non-specialized mammals Kon. Vlaamse Acad. Wetensch. Lett. Sch. Kunsten België 115 126 Brussels
4. The prenatal development of the human first upper permanent molar;Butler;Archs. Oral Biol.,1967
5. Butler , P. M. 1972 Molar wear facets of early Tertiary North American primates Adv. Primatol. in press