World Tourism Organization. (1979). World tourism statistics =: Statistiques du tourisme mondial = Estadisticas del turismo mundial. World Tourism Organization.
Cita Chicago (17th ed.)World Tourism Organization. World Tourism Statistics =: Statistiques Du Tourisme Mondial = Estadisticas Del Turismo Mundial. [Madrid, Spain?]: World Tourism Organization, 1979.
Cita MLA (8th ed.)World Tourism Organization. World Tourism Statistics =: Statistiques Du Tourisme Mondial = Estadisticas Del Turismo Mundial. World Tourism Organization, 1979.
Atenció: Aquestes cites poden no estar 100% correctes.