Zhang, Z.; Huang, Y.; James, H. F.; Hou, L. (2012). "Two Old World vultures from the middle Pleistocene of northeastern China and their implications for interspecific competition and biogeography of Aegypiinae". Journal of Vertebrate Paleontology. 32: 117–124. doi:10.1080/02724634.2012.624146. S2CID85765495.
Zhang, Z.; Huang, Y.; James, H. F.; Hou, L. (2012). "Two Old World vultures from the middle Pleistocene of northeastern China and their implications for interspecific competition and biogeography of Aegypiinae". Journal of Vertebrate Paleontology. 32: 117–124. doi:10.1080/02724634.2012.624146. S2CID85765495.