Authors Year Title
Lee 1981 Permian ammonoid fauna of Venezuela.
Proceedings of the Geological Society of China, 24: 75-86, fig.1-4, pl.1; T'ai-pei, Taiwan.
Miller & Williams 1945 Permian cephalopods from Northern Columbia.
Journal of Paleontology, 19 (4): 347-349, fig.1, pl.51; Tulsa,Oklahoma.