Cita APA (7th ed.)

Harssel, J. V., Van Harssel, J., Jackson, R., & Hudman, L. (2015). National Geographic Learning's visual geography of travel and tourism (Fifth edition.). National Geographic Learning ; Stanford, CT Cengage Learning.

Cita Chicago (17th ed.)

Harssel, Jan Van, Jan Van Harssel, Richard Jackson, i Lloyd Hudman. National Geographic Learning's Visual Geography of Travel and Tourism. Fifth edition. Boston, MA: National Geographic Learning ; Stanford, CT Cengage Learning, 2015.

Cita MLA (9th ed.)

Harssel, Jan Van, et al. National Geographic Learning's Visual Geography of Travel and Tourism. Fifth edition. National Geographic Learning ; Stanford, CT Cengage Learning, 2015.