Fatalities In Germany. (PDF) In: FLIGHT, MARCH 8, 1913.Flightglobal.com, 8. März 1913, S. 292, abgerufen am 27. Juli 2016 (englisch): „While testing, on the 26th ult., a machine built by himself at Cologne, Werntgen fell from a height of 60 metres and received fatal injuries.“
