	Authors	Year	Title
	Bogoslovskaya	1990	Osnovye puti razvitiya i klassifikatsiya pozdnepaleozoyskikh ammonoidey Marathonitaceae i Cyclolobaceae. Trudy Paleontologicheskogo Instituta Akademiya Nauk SSSR, 243: 70-86, fig.1-3; Moskva.
	Miller & Furnish	1940c	Permian ammonoids of the Guadalupe Mountain Region and adjacent areas. Special Papers of the Geological Society of America, 26: 1-242, fig.1-59, pl.1-44; Baltimore.