1928: The Third International After Lenin (A Draft Criticism of the Communist International) [thesis] [Click Here for PDF version] Significant work!
1928: On the Canton Insurrections: Three Letters to Preobrazhensky [letter – 38.3k]
1928: On Max Eastman
1929: The Groupings in the Communist Opposition
1929: Two Letters on the Origin of the Fourth International
1929: Once Again on Brandler-Thalheimer
1929: An Open Letter to the Editorial Board of La Verité
1929: A Letter to the Editorial Board of La Lutte De Classes
1929: Communism and Syndicalism
1929: The Errors in Principle of Syndicalism
1929: The First Contact with Belgium
1929: The Defense of the Soviet Union and the Opposition [essay – 113.4k]
1930: Letter to the Italian Left Communists
1929: Disarmament and the United States of Europe [essay – 34.5k]
1930: The History of the Russian Revolution (book) Significant work!
1930: Open Letter to the All Members of the Leninbund
1930: As Pure and Transparent as Crystal (essay)
1930: An Open Letter to the Italian Left Communists
1930: To the Editorial Board of Prometeo
1930: The Turn in the Communist International and the Situation in Germany Significant work!
1930: Monatte Crosses the Rubicon
1930: World Unemployment and The First Five Year Plan
1930: My Life (autobiography) [Click Here for PDF version – 3.5 megbytes big!] Significant work!