Sources were gathered about the academic concepts connected to entrance fees, the national park‘s websites were examined as well as laws and regulations connected to entrance fees and policy-making.
Aflað var heimilda um þau fræðilegu hugtök sem tengjast gjaldtöku, heimasíður þjóðgarðanna voru skoðaðar og farið yfir lög og reglur er varða gjaldtöku og stefnur.