Spergel, I. (1991). Youth Gangs: Problem and Response. National Youth Gang Information Center.
Cita Chicago Style (17a ed.)Spergel, Irving. Youth Gangs: Problem and Response. National Youth Gang Information Center, 1991.
Cita MLA (9a ed.)Spergel, Irving. Youth Gangs: Problem and Response. National Youth Gang Information Center, 1991.
Precaución: Estas citas no son 100% exactas.