Literature
- Nesis, K.N. 1987. Cephalopods of the world. T.F.H. Publications, Inc., Ltd.
- Poppe, G.T. & Y. Goto 1993. European Seashells. Vol. II. 221 pp. Wiesbaden/Verlag Christa Hemmen.
- Step, E. 1927. Shell life. 421 pp. Frederick Warne & Co., LTD, London.