Loeblich, A.R.Jr. and Wicander, E.R., 1976 Organic-walled microplankton from the Lower Devonian Late Gedinnian Haragan and Bois d'Arc Formations of Oklahoma, U.S.A., Part 1. Palaeontographica, Abteilung B, v.159, no.1-3, p.1-39, pl.1-12.