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. Hampshire, U.K: Waterside Press, 2009.

Cita MLA (9a ed.)

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