Sustainable tourism 68 Tourism 25 Ecotourism 22 SUSTAINABLE TOURISM; 12 SUSTAINABLE TOURISM 11 Sustainable development 7 Climatic changes 5 Culture and tourism 4 ECOTOURISM; 4 Leisure, Recreation and Tourism Economics, (New March 2000) 4 Sustainability 4 TRAVEL / General 4 Tourism and Travel 4 Tourism industry and management 4 Tourism-Management 4 Destinations 3 ECOTOURISM 3 Management 3 Tourism development 3 Tourism-Environmental aspects 3 Carbon dioxide 2 Case studies 2 City planning 2 Destination planning and management tourism 2 Dissertations, Academic (Ph.D) 2 Ecotourism-Case studies 2 Environmental aspects 2 Global tourism 2 Globalisation 2 Heritage tourism 2