OECD Tourism Trends and Policies 2018. Paris : OECD, 2018. 375 s. OECD Tourism Trends and Policies. Available on Internet: <https://www.oecd-ilibrary.org/urban-rural-and-regional-development/oecd-tourism-trends-and-policies-2018/summary/english_8fba5a92-en?parentId=http%3A%2F%2Finstance.metastore.ingenta.com%2Fcontent%2Fpublication%2Ftour-2018-en> ISBN 978-92-64-28738-9.