Cita APA (7a ed.)

Billingsley, R. (2009). Covert human intelligence sources: The "unlovely" face of police work. Waterside Press.

Cita Chicago Style (17a ed.)

Billingsley, Roger. Covert Human Intelligence Sources: The "Unlovely" Face of Police Work. Winchester: Waterside Press, 2009.

Cita MLA (8a ed.)

Billingsley, Roger. Covert Human Intelligence Sources: The "Unlovely" Face of Police Work. Waterside Press, 2009.