Butler, AB (2000). "Chordate Evolution and the Origin of Craniates: An Old Brain in a New Head.". Anat Rec 261 (3): 111–25. doi:10.1002/1097-0185(20000615)261:3<111::AID-AR6>3.0.CO;2-F. PMID 10867629
Mwinyi A, Bailly X, Bourlat SJ, Jondelius U, Littlewood DT, Podsiadlowski L (2010). "The phylogenetic position of Acoela as revealed by the complete mitochondrial genome of Symsagittifera roscoffensis". BMC Evol Biol 10: 309.. PMID 20942955
Barton, RA; Harvey, PH (2000). "Mosaic evolution of brain structure in mammals.". Nature 405 (6790): 1055–8. doi:10.1038/35016580. PMID 10890446
