Natural Resource Economics, (New March 2000) 58 Resources economics 33 Sustainability 33 Water treatment 33 Water management 27 Policy and Planning 24 Tourism and Travel 21 Leisure, Recreation and Tourism Economics, (New March 2000) 19 Social Psychology and Social Anthropology, (New March 2000) 19 Environmental impact 17 Agricultural Economics 16 Case studies 15 Land Resources 14 Marine Resource- economics 14 Water Resources 13 Ecotourism 12 Natural resources 12 Resource management 11 Community Participation and Development, (New March 2000) 10 Natural Resources (General) 10 Pollution and Degradation 10 Agriculture 9 Economic impact 9 Environmental policy 9 Forests 9 Forests and Forest Trees (Biology and Ecology) 9 Tourism 9 Agricultural development 8 Biological Resources (General) 8 Management 8