Ecotourism Tourism 45 Tourism and Travel 22 Leisure, Recreation and Tourism Economics, (New March 2000) 17 Sustainability 15 Natural Resource Economics, (New March 2000) 12 Sustainable development 11 Sustainable tourism 11 Case studies 9 Heritage tourism 8 Tourism development 8 Biological Resources (General) 7 Nature conservation 7 Policy and Planning 7 Environmental impact 6 Social Psychology and Social Anthropology, (New March 2000) 6 Nature tourism 5 Planning 5 Tourist industry 5 Destinations 4 Environmental management 4 Land Resources 4 Management 4 Social impact 4 Tourism impact 4 Alternative tourism 3 Community Participation and Development, (New March 2000) 3 Conservation 3 Culture and tourism 3 Economic impact 3