Microfilms of the National Archives and Records Service, Administration, Washington, D.C., U.S.A.
Original records and excerpts from war diaries concerning Army Group Centre, Federal German Archive/Military Archive, Koblenz.
Dittrich, Helmut: Die Entwicklung des sowjetischen Krafteeinsatzes von Ende MUrz 1943 bis zum Angrijfsbeginn Zitadelle am 5. Juli 1943 (Military History Research Office, 1964).
Secret reports of the Swiss Bureau Hausamann to the Swiss High Command, microfilms, Federal German Archive/Military Archive, Koblenz.