Cita APA (7th ed.)

(1991). World directory of documentation resources and systems for the travel and tourism sector. WTO.

Cita Chicago (17th ed.)

World Directory of Documentation Resources and Systems for the Travel and Tourism Sector. Madrid: WTO, 1991.

Cita MLA (9th ed.)

World Directory of Documentation Resources and Systems for the Travel and Tourism Sector. WTO, 1991.