【序号】:1 【作者】:Gregory J. Retallack, Roger M.H. Smith and Peter D. Ward 【题名】:Vertebrate extinction across Permian–Triassic boundary in Karoo Basin, South Africa 【期刊】:The Geological Society of America 【年、卷、期、起止页码】: September 2003; v. 115; no. 9; p. 1133-1152 【网址】:http://bulletin.geoscienceworld.org/cgi/content/abstract/115/9/1133