Cita APA (7th ed.)

Helfman, G. S., & Burgess, G. H. (2014). Sharks: The animal answer guide. John Hopkins University Press.

Cita Chicago (17th ed.)

Helfman, Gene S., i George H. Burgess. Sharks: The Animal Answer Guide. Baltimore, Maryland: John Hopkins University Press, 2014.

Cita MLA (9th ed.)

Helfman, Gene S., i George H. Burgess. Sharks: The Animal Answer Guide. John Hopkins University Press, 2014.