1. Davidson Black, The lower molar hominid tooth from the Chou Kou Tien deposit. Palaeontologica Sinica Ser. D7, 1 (1927).
2. Davidson Blak, Sinanthropus Pekinensis. The recovery of further fossil remains of this early hominid from the Chou Kou Tien deposit. Science (N. Y.)59 (1929).
3. Davidson Black, Preliminary note on additional Sinanthropus material discovered on Chou Kou Tien deposit 1923. Bull. Geol. Soc. China7 (1929).
4. Gregory, William K., The origin and evolution of the human dentition. J. dent. Res.1920/21.
5. Gregory, William K., The dentition of Dryopithecus and the origin of man. Anthrop. Pap. amer. Mus. Nat. Hist28, TI 1 (1926).