Robertson, Angus (2022). The Crossroads of Civilization: A History of Vienna. Pegasus Books. ISBN9781639361960. Consultado el 12 de noviembre de 2022. «Most serious of the scandals – and a[n] [...] existential crisis for Austria-Hungary – emerged in 1913 [...]. [...] In the biggest spy scandal in Austrian history, it emerged that Redl committed treason with the Russians [...].»
