Inside Out Library · ExploreDrag of Prestone and Oil Radiators on the YO-31A Airplane (1935)NASA Technical Reports Server (NTRS) · leaf 5NASA Technical Reports Server (NTRS)Internet Archive · NASA Technical Reports · Public domain (US government work). Free to use for anything.More pictures from Drag of Prestone and Oil Radiators on the YO-31A AirplaneMore like this
