BioStor
 | The genera of Lactuceae (Compositae) in the southeastern United States B S Vuilleumier (1973) Journal of the Arnold Arboretum 54: 42-93 |
 | Subtribes of principally North American genera of Cichorieae (Compositae) B G Baldwin and J-K Lee (2004) Novon 14: 309-313 |