1. Material and process specifications; Jan. 10-June 10, 1941. Bookmark Corporate/Agency Authors: Air Corps Publisher: Air Corps Date: Jan. 6-June 3, 1941 SuDoc number: W 87.3:23/49-54
2. Bulletin 40 and 44; Jan. 2 and Feb. 28, 1941. Bookmark Corporate/Agency Authors: Air Corps Publisher: Air Corps Date: 1941 SuDoc number: W 87.3:40,44