Gregory، William K. (1985). "The New Anthropogeny: Twenty-Five Stages of Vertebrate Evolution From Silurian Chordate to Man". Science. ج. 77 ع. 1985: 29–40. DOI:10.1126/science.77.1985.29. PMID:17792389.
Gregory، William K. (1985). "The New Anthropogeny: Twenty-Five Stages of Vertebrate Evolution From Silurian Chordate to Man". Science. ج. 77 ع. 1985: 29–40. DOI:10.1126/science.77.1985.29. PMID:17792389.