Cita APA (7a ed.)

Fennell, D. A. (1999). Ecotourism: An introduction. Routledge.

Cita Chicago Style (17a ed.)

Fennell, David A. Ecotourism: An Introduction. London [etc.]: Routledge, 1999.

Cita MLA (9a ed.)

Fennell, David A. Ecotourism: An Introduction. Routledge, 1999.