- Die NSDAP. Die Parteiorganisation 1919-1945 (1937): This early work focused on the organizational structure and development of the Nazi Party (NSDAP).
- Wehrmacht und Partei. Hitlers Bündnis mit der Führungsschicht des Heeres (1960): This influential book examined the complex relationship between the Nazi Party and the German military leadership, specifically focusing on the period leading up to World War II.
- The Old Army: German Officers, Military Tradition, and the Rise of Nazism, 1918-1933 (1974): Translated from German, this book provided an analysis of the role of traditional German military values and the impact of World War I on the rise of Nazism within the German army.
- Die Militarisierung der Innenpolitik im Dritten Reich (1975): This book investigated the militarization of internal German politics during the Nazi era.
- Bismarcks Sturz (1984): Suhr's biography of Otto von Bismarck focused on the factors leading to Bismarck's dismissal as Chancellor of the German Empire in 1890.
In addition to these major publications, Suhr wrote numerous articles, essays, and book reviews on various aspects of German history, particularly the Nazi period. His works are recognized for their thorough research and insightful analysis, and they have had a significant impact on the study of modern German history.