Claudia Koonz The Nazi Conscience. Cambridge, Mass.: The Belknap Press of Harvard University Press, 2003.
Karl Dietrich Bracher "Stages of Totalitarian "Integration" (Gleichschaltung): The Consolidation of National Socialist Rule in 1933 and 1934" pages 109-128 from Republic To Reich The Making of the Nazi Revolution Ten Essays edited by Hajo Holborn, New York: Pantheon Books, 1972.
Everett HughesThe "Gleichschaltung" of the German Statistical Yearbook: A Case in Professional Political Neutrality. The American Statistician Vol. IX (Dec., 1955, pp. 8-11.
