Tolong jelaskan mengenai Sumber utama dari Anschluss dalam bahasa melayu

Gedye, George Eric Rowe. Betrayal in Central Europe. Austria and Czechoslovakia, the Fallen Bastions. New and revised edition. Harper & Brothers, New York 1939. Paperback reissue, Faber & Faber, 2009. ISBN 978-0571251896.

Schuschnigg, Kurt. The brutal takeover: The Austrian ex-Chancellor's account of the Anschluss of Austria by Hitler (London: Weidenfeld and Nicolson, 1971) ISBN 0-297-00321-6.