1. Fine structure of the turbellarian epidermis;Bedini,1974
2. Intracytoplasmic ciliary elements in epidermal cells of Syndesmis echinorum and Paravortex cardii (Platyhelminthes, Dalyellioida);Cifrian;J. Morphol.,1992
3. Phylogenetic relationships within the Platyhelminthes;Ehlers,1985
4. Ehlers, U., 1985b. Das phylogenetische System der Plathelminthes. Fischer, G., Stuttgart, 317pp.
5. Comments on phylogenetic system of the Platyhelminthes;Ehlers;Hydrobiologia,1986