Barker, F.K., G.F. Barrowclough, and J.G. Groth (2002), A phylogenetic hypothesis for passerine birds: Taxonomic and biogeographic implications of an analysis of nuclear DNA sequence data, Proc. Royal Soc. B269, 295-308. Pubmed ID 11839199 DOI: 10.1098/rspb.2001.1883
Barker, F.K., A. Cibois, P. Schikler, J. Feinstein, and J. Cracraft (2004), Phylogeny and diversification of the largest avian radiation, Proc. Natl. Acad. Sci.101(30), 11040-11045. DOI: 10.1073/pnas.0401892101
Barker, F.K., G.F. Barrowclough, and J.G. Groth (2002), A phylogenetic hypothesis for passerine birds: Taxonomic and biogeographic implications of an analysis of nuclear DNA sequence data, Proc. Royal Soc. B269, 295-308. Pubmed ID 11839199 DOI: 10.1098/rspb.2001.1883