Tinn, O. 1998.
The Ordovician clitambonitidine brachiopod genus Vellamo in Estonia.Proceedings of the Estonian Academy of Sciences. Geology47,
3,195-216.
Öpik, A. 1934.
Über Klitamboniten.Acta et Commentationes Universitatis Tartuensis XXVI,
5,1-239.