Roberto Marotta, Marco Ferraguti, Christer Erséus, Lena M. Gustavsson (2008): Combined-data phylogenetics and character evolution of Clitellata (Annelida) using 18S rDNA and morphology. Zoological Journal of the Linnean Society 154: 1–26. doi:10.1111/j.1096-3642.2008.00408.x
Mark E. Siddall, Kathleen Apakupakul, Eugene M. Burreson, Kathryn A. Coates, Christer Erséus, Stuart R. Gelder, Mari Källersjö, Henry Trapido-Rosenthal (2001): Validating Livanow: Molecular Data Agree That Leeches, Branchiobdellidans, and Acanthobdella peledina Form a Monophyletic Group of Oligochaetes. Molecular Phylogenetics and Evolution 21 (3): 346–351. doi:10.1006/mpev.2001.1021
