1. Al-Hagla, K (2004) Cultural Sustainability: An Asset of Cultural Tourism Industry. Clusters, Districts, and Networks of Tangible, and Intangible Material. Cultural Heritage in the Non-Eu Mediterranean Countries. University of Turin, Department of Economics, EBLA Center, Turin, Italy.
2. Archer, BH and Fletcher, JE (1990) Multiplier Analysis in Tourism. Les Cahiers du Tourisme. Series C. Aix-en-Provence: Centre Des Hautes Etudes Touristiques.
3. Ashley, C, Dilys Roe, D and Goodwin, H (2001) Pro-Poor Tourism Strategies: Making Tourism Work for the Poor: A review of experience. Pro-Poor Tourism Report No.1 Overseas Development Institute, Russell Press, Nottingham.
4. Ashworth, Gregory J (1992) Heritage and tourism: An argument, two problems and three solutions. In Spatial implications of tourism, CAM Fleischer van Roojen (ed.). Geo Pers, Groningen, the Netherlands.
5. From history to heritage: from heritage to identity: in search of concepts and models;Ashworth,1994