Here are some of his key works:
* "The Roosevelt Era: 1933-1945" (1963): This book provides an insightful analysis of the social and political landscape of the United States during President Franklin D. Roosevelt's tenure.
* "Rosa Luxemburg" (1969): This biography of the revolutionary socialist is considered a seminal work in understanding Luxemburg's life and ideas.
* "The State and the Structure of Power in Austria-Hungary" (1964): This academic work explores the complexities of the Austro-Hungarian Empire's political structure and the dynamics of power within it.
* "The Limits of State Power: A Study of the Austro-Hungarian Empire" (1965): This book further delves into the limitations of state power in the context of the Habsburg Empire.
* "The Jews of Vienna: A Study in the History of a Community" (1984): This book examines the history of the Jewish community in Vienna, focusing on its social, economic, and cultural aspects.
Nettl also edited various scholarly collections and contributed numerous articles to academic journals. His works are characterized by their meticulous research, nuanced analysis, and deep understanding of the historical contexts he studied. He is remembered as a significant figure in the field of European history, particularly for his contributions to the study of Austria and the Austro-Hungarian Empire.