^Conodonts from the Chappel limestone of Texas. W.H. Hass, USGS Numbered Series, Professional Paper 294, chapter J, pages 365-399, 1959
^On Classification of Pridoli (Silurian)-Lochkovian (Devonian) Spathognathodontidae (Conodonts). Murphy M.A., Valenzuela-Ríos J.I. and Carls P., 2004, University of California, Riverside Campus Museum Contribution, 6, pp. 1-25, 3 Figs. PDF
A new Ludlow (Late Silurian) Spathognathodontidae (Conodonta) from Bohemia with incipient alternating denticulation. P. Carls, L. Slavík and José Ignacio Valenzuela-Ríos, Neues Jahrbuch für Geologie und Paläontologie - Monatshefte, September 2005, 9, pages 547–565.