The Indian Constitution has borrowed several features from the constitutions of various countries. Single Citizenship is a concept borrowed from the United Kingdom. Judicial Review, the power of courts to examine the constitutionality of legislative and executive actions, is inspired by the system in the United States of America. The Directive Principles of State Policy (DPSP) are based on the Irish Constitution. The concept of the Concurrent List, which enumerates subjects on which both the Union and State governments can legislate, is borrowed from the Australian Constitution.