Williamson, J. L. (1955). A survey of police services and problems in the Philippines. Institute of Public Administration, University of the Philippines.
Lua i Stíl Chicago (17ú heag.)Williamson, Jeter L. A Survey of Police Services and Problems in the Philippines. Manila: Institute of Public Administration, University of the Philippines, 1955.
Lua MLA (9ú heag.)Williamson, Jeter L. A Survey of Police Services and Problems in the Philippines. Institute of Public Administration, University of the Philippines, 1955.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.