Reference

S. Raychaudhuri, D.P. Haldar, M.M.S. Chakravarty (1968): Observations on a new astomate ciliate., Anoplophrya pheretimii, from the earthworm, Pheretima posthuma (L. Yaill) – Archiv für Protistenkunde – 111_1968: 228 - 235.