Cita APA (7a ed.)

Gibbs, P. E., & Kermack, D., M. (1977). British sipunculans: Keys and notes for the identification of the species. Academic Press.

Cita Chicago Style (17a ed.)

Gibbs, Peter Edwin, y Doris Kermack, M. British Sipunculans: Keys and Notes for the Identification of the Species. London: Academic Press, 1977.

Cita MLA (8a ed.)

Gibbs, Peter Edwin, y Doris Kermack, M. British Sipunculans: Keys and Notes for the Identification of the Species. Academic Press, 1977.