What is one complete international law about tourism (it can be for the US or London or China, etc)?
There is no central online database the simply lists international tourism laws. However, the World Tourism Organization has set up LEXTOUR which holds a database of international tourism law. If your have no access to the required laws in your course work (assuming this question is prompted by a course requirement), then you can contact LEXTOUR at email@example.com . They may be willing to assist you in the needs of your studies.