↑ Shevyrev, A.A. (2005). "The Cephalopod Macrosystem: A Historical Review, the Present State of Knowledge, and Unsolved Problems: 1. Major Features and Overall Classification of Cephalopod Mollusks". 'Paleontological Journal. 39 (6): 606–614. Translated from Paleontologicheskii Zhurnal No. 6, 2005, 33-42.
↑ Shevyrev, A. A. (2006). "The cephalopod macrosystem; a historical review, the present state of knowledge, and unsolved problems; 2, Classification of nautiloid cephalopods". Paleontological Journal. 40 (1): 46–54. doi:10.1134/S0031030106010059. ISSN0031-0301. Unknown parameter |quotes= ignored (help)
↑ Bather, F.A. (1888a). "Shell-growth in Cephalopoda (Siphonopoda)". Annals and Magazine of Natural History. Series 6, Vol. 1: 298–310. Unknown parameter |quotes= ignored (help)
