Cita APA (7a ed.)

Pennell, S., Curtis, C., & Henderson, J. H. (19). Guardian angels: An assessment of citizen response to crime. San Diego Assoc. of Governments.

Cita Chicago Style (17a ed.)

Pennell, Susan, Christine Curtis, y Joel H. Henderson. Guardian Angels: An Assessment of Citizen Response to Crime. San Diego, CA: San Diego Assoc. of Governments, 19.

Cita MLA (9a ed.)

Pennell, Susan, et al. Guardian Angels: An Assessment of Citizen Response to Crime. San Diego Assoc. of Governments, 19.