Authors Year Title
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.
Smith 1927 Permian ammonoids of Timor.
Jaarboek van het Mijnwezen in Nederlandsch-Indie, 55 (for 1926): 1-58, pl.1-16; 'S Gravenhage.
Tharalson 1984 Revision of the Early Permian ammonoid family Perrinitidae.
Journal of Paleontology, 58 (3): 804-833, fig.1-24, 1tab.; Lawrence, Kansas.