Reference

Schlegel, H.J. Elwood, M.L. Sogin (1991): Molecular evolution in hypotrichous ciliates: sequence of the small subunit ribosomal RNA genes from Onychodromus quadricornutus and Oxytricha granulifera (Oxytrichidae, Hypotrichida, Ciliophora) – J. Mol. Evol. – 32: 64 - 69.