↑Sibley, C.G.; Ahlquist, J.E.; Monroe, B.L. (1988). "A classification of the living birds of the world based on DNA-DNA hybridization studies". Auk. Cilt105. s.409–423.
↑Chubb, A. (2004). "New nuclear evidence for the oldest divergence among neognath birds: the phylogenetic utility of ZENK(i)". Molecular Phylogenetics and Evolution. Cilt30. ss.140-151.