1. Model organisms in the study of development and disease;Bier,2004
2. Summary statistics for globally threatened species. Table 1: numbers of threatened species by major groups of organisms (1996–2014);The World Conservation Union,2014
3. The Vertebrate Body;Romer,1949
4. Patterns in Nature;Stevens,1974
5. Analysis of Vertebrate Structure;Hildebrand,2001