Cita APA (7a ed.)

Pennell, S., Curtis, C., & Henderson, J. H. (1985). Guardian angels. Guardian angels an assessment of citizen response to crime.

Cita Chicago Style (17a ed.)

Pennell, Susan, Christine Curtis, y Joel H. Henderson. "Guardian Angels." Guardian Angels an Assessment of Citizen Response to Crime 1985.

Cita MLA (8a ed.)

Pennell, Susan, et al. "Guardian Angels." Guardian Angels an Assessment of Citizen Response to Crime, 1985.