"History (1930–1945)". Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart. Archived from the original on 19 July 2011. Retrieved 3 September 2010.
F.L. Wattendorf (May 1946) "Reports on selected topics of German and Swiss aeronautical developments", in Toward New Horizons, link from Governmentattic
"History (1930–1945)". Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart. Archived from the original on 19 July 2011. Retrieved 3 September 2010.