NFPA 140 Standard on Motion Picture and Television Production Studio Soundstages and Approved Production Facilities, 2004 ed. http://www.gushebooks.org/b62ix_download-motion-pi cture-production-facilities-pdf-file.pdf, (Std: Motion Picture and Television Prod Studio Soundstages and Approved Prod Fcilty - Amer) {257 NFC}