(ням.) William L. Patch. Heinrich Bruning and the Dissolution of the WeimarRepublic. — New York: Cambridge University Press, 1998. — 358 с. — ISBN 0521624223
Congress, Second Session. — 1954. — 537 с. John Hiden. The Baltic States and Weimar Ostpolitik. — Cambridge University Press, 2002. — 292 с. Министерство иностранных