Strong-Tight Packaging : Used for domestic shipment of materials with low levels of radioactivity with a low hazard and historical safety record such as depleted or natural uranium and rubble. NFPA 472, 2002 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}