EIGHT SOFTCOVER BOOKS FROM THE PUBLIC ADDRESS SERIES BY NATIONAL RADIO INSTITUTE.  1951 OR 1952 EDITIONS. 
  1. P.A. TRANSMISSION SYSTEMS
  2. ACOUSTICS IN PUBLIC ADDRESS WORK
  3. COMMERCIAL P.A. SYSTEMS
  4. MAINTENANCE OF P.A. SYSTEMS
  5. INTRO TO PUBLIC ADDRESS
  6. SPECIAL P.A. SYSTEMS-1953 EDITION
  7. HOW TO ELIMINATE DISTORION SERVICING LOUDSPEAKERS 42RH-1-NOT IN PHOTO
  8. HOW LOW CONE TYPE LOUDSPEAKERS WORK. 27FR-2 NOT IN PHOTO 1950 EDITION
02-2024 REV