[CITATION][C] UNWTO tourism highlights
World Tourism Organization - 2017 - World Tourism Organization
[CITATION][C] UNWTO tourism highlights
U UNWTO - 2016 - UNWTO Madrid
[CITATION][C] UNWTO tourism highlights
United Nations World Tourism Organization - UNTWO, 2014
[CITATION][C] UNWTO tourism highlights 2017 edition
United Nations World Tourism Organization - 2017 - UNWTO Madrid