APA (7th ed.) Citation

Roper, C. F. E., Young, R. E., & Voss, G. L. An illustrated key to the families of the order Teuthoidea (Cephalopoda).

Chicago Style (17th ed.) Citation

Roper, Clyde F. E., Richard E. Young, and Gilbert L. Voss. An Illustrated Key to the Families of the Order Teuthoidea (Cephalopoda).

MLA (9th ed.) Citation

Roper, Clyde F. E., et al. An Illustrated Key to the Families of the Order Teuthoidea (Cephalopoda).