As applied to wildland fire fighting: A helmet without the suspension system, accessories, and fittings. NFPA 1977, 2005 ed. As applied to fire fighting: The outermost layer of the protective ensemble element composite. NFPA 1976, 2000 ed
National Fire Protection Association, Illustrated Dictionary of Fire Service Terms, Jones & Bartlett Publishers, MA. USA 2006. https://books.google.com.kw/books?id=W0WIRa3Gl4QC& printsec=frontcover&source=gbs_ge_summary_r&cad=0# v=onepage&q&f=false, (Fr Srvc - Amer) {141}