References Agarwal, V.B., and Yochum, G.R. (1999). Tourist spending and race of visitors. Journal of Travel Research, 38(2), 173-178. Alberini, A. (1995). Efficiency vs. Bias of Willingness-to-estimates Bivariate and Internal-Data Models, Journal of Environmental Economics and Management 29: pp 169-80. Alberini, A., et al. (1997). Modelling Responsive Incentive effects in Dichotomous Choice Contingent Valuation Data. Land Economics 73: pp 309-24. Bann, C. (1998). The Economic Valuation of Tropical Forest Land Use Option: A Manual for Researchers, Economy and Environment Program for Southeast Asia, Singapore. Boo, E. (1990). Eco-tourism: The Potentials and Pitfalls', Washington, D.C.:WWF. Bhattacharya, P. and S. Kumari (2004). "Application of Criteria and Indicator for Sustainable Ecotourism: Scenario under Globalization", IASCP Bi-Annual Conference on "The Commons in an Age of Global Transition: Challenges, Risk and Opportunities" at Oaxaca, Mexico from 9-14 August, 2004. Bird, R. M. (1992). "Taxing tourism in developing countries", World Development, 20, 1145-58. Bushell, R. (2003). "Balancing Conservation and Visitation in Protected Areas", in Ralf Buckley, Catherine Pickering, David Bruce Weaver (eds.) in Nature-Based Tourism, Environment and Land Management. Ceballos-Lascurain, H. (1991). Tourism, ecotourism, and protected areas, In Kusler, J. A. (ed.) Ecotourism, Resource Conservation, Ecotourism and Resource Conservation Project, Berne, New York, pp. 24.30. Chase, L.C., Lee, D.R., Schulze, W.D. and Anderson, D.J. (1998). "Eco-Tourism Demand and Differential Pricing of National Park Access in Costa Rica", Land Economics, 74(4), 466-482. Cooper, C. (2006). Classic Review of Tourism, Viva Books Private Limited. Copeland, B. R. (1991). "Tourism, Welfare and De-industrialization in a Small Open Economy", Economics, London School of Economics and Political Sciences, 58(232), 515-529. Cottrell, S.P. (2003). "Influence of Socio Demographics and Environmental Attitudes on General Responsible Environmental Behaviour among Recreational Boaters", Environmental Behaviour, 35(3), 347-375. Crompton, J. L. et al (1993). "Conceptualization of multi-destination pleasure trip decisions", Annals of Tourism Research, 20, 289-301. Fennell, B. A. (2003). Ecotourism: An Introduction, Routledge (UK). Greene, W.H., (2000). Econometric Analysis, 4th ed. Prentice Hall, New Jersey. Hamilton, L. C. (1992). Regression with Graphics: A Second Course in Applied Statistics. Pacific Grove, Ca: Brooks/Cole Publishing Company. Honey, M. (1999). Ecotourism and Sustainable Development: who owns paradise?, Island Press. Kristrom, B. and P. Riera (1996). 'Is the Income Elasticity of Environmental Improvements Less Than One?', Environmental and Resource Economics 7, 45-55. Kristrom, B. and Riera, P. (1996). Is the Income Elasticities of Environmental Improvements Less than One? Environmental and Resources Economics, 7. Lama, M. P. (1994). Sikkim: Society, Polity, Economy, Environment, Indus Publishing. Mason, P. (2003). Tourism Impacts, Planning and Management, Elsevier. McCool, S. F. and R. N. Moisey (2001). Tourism, Recreation, and Sustainability: linking culture and the environment, CABI Publishing. Miles, D., Pereyra, A. and Rossi, M. (2002). The Consistent estimation of Income Elasticity of Environmental Amenities in Uruguay. Studios Economics, 17. Mok, C., and Armstrong, R.W. (1995). "Leisure travel destination choice criteria of Hong Kong residents", Journal of Travel and Tourism Marketing, 4(1), 99-104. Odunga, P. and H. Folmer (2004). "Profiling Tourists for Balanced Utilization of Tourism-Based Resources in Kenya", NOTA DI LAVORO 23.2004. Pindyck, R.S. and D.L. Rubinfeld (1976). Econometrics Models and Econometric Forecasts. New York, NY: McGraw Hill Book Co. Ray, A. and S. Das (2001). Sikkim: A Traveller's Guide, Orient Blackswan. Tapsuwan, S., Brennan, D and Ingram, G. (2007). 'The welfare costs of outdoor water restrictions', Australian Journal of Agricultural and Resource Economics, vol. 51, no. 3, 243-61. Thomas-Hope, E. M. and I. Goodbody (2002). Natural Resource Management For Sustainable Development In The Caribbean, University of Oklahoma Press. Tisdel, C. (1987). 'Tourism, the environment and profit', Economics Analysis and Policy, 17(1), 13-30. Tisdell, C.A. (1996). "Ecotourism, Economics and the Environment: Observations from China," Journal of Travel Research, Vol. 34, No. 4, pp. 11-19. Wearing, S. and J. Neil (2001). 'Expanding Sustainable Tourism's Conceptualization: Ecotourism, Volunteerism and Serious Leisure', in Stephen F. McCool, R. Neil Moisey (eds) Tourism, Recreation, and Sustainability: linking culture and the environment. Weaver, P.A., McCleary, K.W., Lepisto, L., and Damonte, L.T. (1994). The relationship of destination selection attributes to psychological, behavioural and demographic variables. Journal of Hospitality and Leisure Marketing, 2(2), 93-109.