Mass thickness manual for walls, floors, and roofs.
Series: Its TR- -- 68
Publisher: Defense Civil Preparedness Agency
Published: 1973
Place of publication: [Washington, D.C.]
Language: eng
Number of pages: 48
Subjects: Building -- Tables.; Nuclear bomb shelters.; Building materials -- Standards.; Civil defense -- United States.
Genres: Tables.
Notes: Cover title.

Supersedes TR-68 dated June 1971 which may be used.