Table of Contents for Madge, S. and Burn, H.: Crows and Jays.: Curl-crested Jay Cyanocorax cristatellus 84 Genus Cyanocorax Genus Sub-genus Cyanocorax
http://www.pupress.princeton.edu/TOCs/c7150.html

Corvidae checklist: Bushy-crested Jay San Blas Jay Yucatan Jay Purplish-backed Jay Curl-crested Jay
http://www.wam.umd.edu/~csparr/corvidweb/checklist.htm

ADW: Cyanocorax: Classification: ...chested jay). Species Cyanocorax beecheii (purplish-backed jay). Species
http://animaldiversity.ummz.umich.edu/site/accounts/classification/Cyanocorax.html

Classification of birds of South America Part 09: Jay 2 Cyanolyca pulchra Beautiful Jay 5 Cyanocorax violaceus Violaceous Jay 6 Cyanocorax
http://www.museum.lsu.edu/~Remsen/SACCBaseline09.html