Zhang, X.G.; Hou, X.G. (2004), "Evidence for a single median fin-fold and tail in the Lower Cambrian vertebrate, Haikouichthys ercaicunensis", Journal of Evolutionary Biology, 17 (5): 1162–1166, doi:10.1111/j.1420-9101.2004.00741.x, PMID15312089
Zhang, X.G.; Hou, X.G. (2004), "Evidence for a single median fin-fold and tail in the Lower Cambrian vertebrate, Haikouichthys ercaicunensis", Journal of Evolutionary Biology, 17 (5): 1162–1166, doi:10.1111/j.1420-9101.2004.00741.x, PMID15312089