Citazione APA

Harssel, J. V., Jackson, R., & Hudman, L. (2015). National geographic learning's visual geography of travel and tourism (5th edition.). National geographic learning.

Stile di citazione Chicago

Harssel, Jan Van, Richard Jackson, e Lloyd Hudman. National Geographic Learning's Visual Geography of Travel and Tourism. 5th edition. USA: National geographic learning, 2015.

Citazione MLA

Harssel, Jan Van, et al. National Geographic Learning's Visual Geography of Travel and Tourism. 5th edition. National geographic learning, 2015.