↑Hackett, S.J.; et al. (2008). «A Phylogenomic Study of Birds Reveals Their Evolutionary History». Science. 320: 1763–8. PMID18583609. doi:10.1126/science.1157704
↑Kimball, R.T. et al. (2013) Identifying localized biases in large datasets: A case study using the Avian Tree of Life. Mol Phylogenet Evol. doi:10.1016/j.ympev.2013.05.029