↑ abc et d(en) Zhou, Zhonghe & Zhang, Fucheng (2006): A beaked basal ornithurine bird (Aves, Ornithurae) from the Lower Cretaceous of China. Zool. Scripta 35: 363–373
↑(en) C. Gao, L. M. Chiappe, F. ZHang, D. L. Pomeroy, C. Shen, A. Chinsamy, and M. O. Walsh. 2012. A subadult specimen of the Early Cretaceous bird Sapeornis chaoyangensis and a taxonomic reassessment of sapeornithids. Journal of Vertebrate Paleontology 32(5):1103-1112
↑(en) The early evolutionary history of birds, Chiappe et Dike, J. paleont. Soc. Korea, vol 22, No.1, (2006): p 133-151