Travel & tourism's enormous economic contribution : a cold review of the WTTC/WEFA Group Research / by Michael J. Boskin
Les européens et les vacances 1997-1998 / Commission Européenne. Direction Générale XXIII
História e antologia da literatura portuguesa : séculos XIII-XIV / coord. Isabel Allegro de Magalhães, Cristina Monteiro
Visitor payback : encouraging tourists to give money voluntarily to conserve the places they visit / Richard Denman, Peter Ashcroft