https://kompy.info/samarqand-iqtisodiyot-va-servis-instituti.html?page=10
https://www.tutorialspoint.com/tourism_management/tourism_management_products_and_services.htm
https://www.google.com/search?q=google+translate&oq=go&aqs=chrome.0.69i59l2j69i57j0i131i433j69i60l4.1519j0j7&sourceid=chrome&ie=UTF-8
https://xreferat.com/103/1110-1-osnovnye-i-dopolnitel-nye-uslugi-v-sfere-turizma.html
https://opentextbc.ca/introtourism2e/chapter/1-conclusion/
