Hermann Rauschning in his 1940 book Hitler Speaks: A Series of Political Conversations With Adolf Hitler on His Real Aims 1934 records Adolf Hitler as speaking of an inescapable battle against both Pan-Slavism and Neo-Slavism. The authenticity of the book is controversial: some historians, such as Wolfgang Hänel, claim that the book is a fabrication, whereas others, such as Richard Steigmann-Gall, Ian Kershaw and Hugh Trevor-Roper, have avoided using it as a reference due to its questionable authenticity. Rauschning records Hitler as saying of the Slavs:[49]