Aerial attack-protective and defensive measures: Plane for underground factories (Japanese). Report No. 51b(20)(d), USSBS Index Section 2

Aerial attack-protective and defensive measures: Underground or dispersal program (Japanese). Report No. 51b(20)(b), USSBS Index Section 2

Aerial attack-protective and defensive measures: Notes and work sheets. Report No. 51b(20)(a), USSBS Index Section 2

Aerial attack-protective and defensive measures: Effect of the war on industry (Japanese). Report No. 51b(20)(c), USSBS Index Section 2