Barker, F. Keith; Barrowclough, George F. & Groth, Jeff G. (2002): A phylogenetic hypothesis for passerine birds: taxonomic and biogeographic implications of an analysis of nuclear DNA sequence data. Proceedings of the Royal Society B269 (1488): 295–308. doi:10.1098/rspb.2001.1883PDF fulltext
Barker, F. Keith; Barrowclough, George F. & Groth, Jeff G. (2002): A phylogenetic hypothesis for passerine birds: taxonomic and biogeographic implications of an analysis of nuclear DNA sequence data. Proceedings of the Royal Society B269 (1488): 295–308. doi:10.1098/rspb.2001.1883PDF fulltext