Study on visa facilitation in the silk-road countries / World Tourism Organization
Estudo internacional sobre viajantes em trânsito / Organização Mundial do Turismo
Seminário - estadisticas de frontera en los paises europeos: metodologia de la estadistica de movimentos turisticos en fronteras terrestres / Organização Mundial de Turismo
Voyages a l'étranger formalités de frontiéres / Organisation Mondiale du Tourisme
Proceedings of the fifth international conference of National Travel Organisations and the sixteenth general assembly of the International Union of Official Travel Organisations held in Dublin Castle, october 17-20, 1950 / World Tourism Organization