Willigen, Niels van (2013). Peacebuilding and International Administration: The Cases of Bosnia and Herzegovina and Kosovo. Routledge. pp. 16–. ISBN978-1-134-11718-5.: "Crawford (2006) distinguishes three different types of protectorates: protected states, international protectorates, and colonial protectorates. First, protected states are entities which still have substantial authority in their internal affairs, retain some control over their foreign policy, and establish their relation to the protecting state on a treaty or another legal instrument. Protected states still have qualifications of statehood."
