Inside Out Library · ExploreRelative Economy of Different Methods of Airplane Construction (1931)NASA Technical Reports Server (NTRS) · leaf 48Kf.A.CA. Technical Memorandum No.618 Figs. 8a, 11 Fig.11 Wing tanks in nC 36"NASA Technical Reports Server (NTRS)Internet Archive · NASA Technical Reports · Public domain (US government work). Free to use for anything.More pictures from Relative Economy of Different Methods of Airplane ConstructionMore like this
