Eye Colors?" (页面存档备份,存于互联网档案馆) (summarizing Frost, P. 2006. European hair and eye color - A case of frequency-dependent sexual selection? Evolution and
Database. Results for NGC 6745. [2006-11-25]. (原始内容存档于2011-05-14). A Bird's Eye View of a Galaxy Collision - Fast Facts. [2008-02-26]. (原始内容存档于2016-07-08)
Gregory, T.R. 2002. A bird's-eye view of the C-value enigma: genome size, cell size, and metabolic rate in the class Aves. Evolution 56: 121-130. Gregory, T