Reference

Sabine Agatha, M.C. Strüder-Kypke (2007): Phylogeny of the order Choreotrichida (Ciliophora, Spirotricha, Oligotrichea) as inferred from morphology, ultrastructure, ontogenesis, and SSrRNA gene sequences – Journal of Eukaryotic Microbiology – 43: 37 - 63.