Authors Year Title
Miller & Unklesbay 1943 The siphuncle in Late Paleozoic amonoids.
Journal of Paleontology, 17 (1): 1-25, fig.1-9, pl.1-5; Tulsa,Oklahoma.
Ruzhencev 1956 Nizhnepermskiye ammonity Yuzhnogo Urala. II. Ammonity Artinskogo yarusa.
Trudy Paleontologicheskogo Instituta Akademiya Nauk SSSR, 60: 1-275, fig.1-97, pl.1-39; Moskva.