| author | date |  | title | journal / publication | 
Hyman LH | 1931 |  
 | Studies on the morphology, taxonomy, and distribution of North American triclad Turbellaria. IV. Recent European revisions of the triclads, and their appl to American forms, with a key to the latter, and new notes on distribution. | Trans Am Microsc Soc 50:316-335 |