APA (7th ed.) Citation

Boer, M. d. (1991). Schengen: Intergovernmental scenario for European police co-operation. A system of European police co-operation in 1992.

Chicago Style (17th ed.) Citation

Boer, Monica den. "Schengen: Intergovernmental Scenario for European Police Co-operation." A System of European Police Co-operation in 1992 1991.

MLA (9th ed.) Citation

Boer, Monica den. "Schengen: Intergovernmental Scenario for European Police Co-operation." A System of European Police Co-operation in 1992, 1991.