BioStor
 | Notes on the worm snakes of the southwest, with descriptions of two new subspecies Laurence M Klauber (1931) Transactions of the San Diego Society of Natural History 6: 333-352 |
 | Catalogue of the Neotropical Squamata. Part I. Snakes James A Peters and Braulio Orejas-Miranda (1970) Bulletin United States National Museum 297: 1-347 |