Saunders WB, Work DM. 1999. The Cravenoceras-Glaphyrites dilemma: ammonoid sutures vs. shell shape in the mid-Carboniferous, In A. Yu. Rozanov and A. A. Shevyrev (eds.), Fossil Cephalopods: Recent Advances in Their Study, Russian Academy of Sciences Paleontological Institute, Moscow. p. 125-137.