Ericson, P. G. P., L. Christidis, A. Cooper, M. Irestedt, J. Jackson, U. S. Johansson, & J. A. Norman. 2002. A Gondwanan origin of passerine birds supported by DNA sequences of the endemic New Zealand wrens. Proceedings of the Royal Society of London Series B 269:235–241. PDF[mrtav link]
pnas.org
F. Keith Barker, Alice Cibois, Peter Schikler, Julie Feinstein< & Joel Cracraft: Phylogeny and diversification of the largest avian radiation. PNAS, July 27, 2004, Vol. 101, no. 30, PDF
