Pishgahifard, Zahra, and Hassan Salehi. 2014. “Geo-Economics and Considerations on the Tourism Industry With Emphasis on Historical Cities Tourism and Ecotourism in Iran”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 15 (1):301-10. https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/2155.