American National Standards Institute, American National Standards Institute, National Fire Protection Association (Estados Unidos), National Fire Protection Association (Estados Unidos), Languages Worldwide, & Languages Worldwide. (2007). Código Nacional de Alarmas de Incendio: NFPA 72 (Edición 2007.). Quincy, Mass.: National Fire Protection Association.

American National Standards Institute, American National Standards Institute, National Fire Protection Association (Estados Unidos), National Fire Protection Association (Estados Unidos), Languages Worldwide, and Languages Worldwide. Código Nacional De Alarmas De Incendio: NFPA 72. Edición 2007. Quincy, Mass.: National Fire Protection Association, 2007.

American National Standards Institute, et al. Código Nacional De Alarmas De Incendio: NFPA 72. Edición 2007. Quincy, Mass.: National Fire Protection Association, 2007.