English, Jack
Police training manual / Jack English, Brian English
McGraw-Hill, 1992
 Buku Teks
Smart, Huw
Blackstone's police Q and A : general police duties 2006
Oxford University Press, 2006
 Buku Referensi
Students engineering manual. Coordinating
edited by George A. Hawkins
McGraw-Hill, 1968
 Buku Teks
Students engineering manual
cordinating editor, Geoge A. Hawkins
McGraw-Hill, 1968
 Buku Teks
Smart, Huw
Blackstone's police Q and A : crime 2006
Oxford University Press, 2006
 Buku Referensi