- Avrich, Paul (1984). The Haymarket Tragedy. Princeton University Press. ISBN 978-0-691-04711-9. https://books.google.com/books?id=lET_DwAAQBAJ&pg=PA48
- Goyens, Tom (2007). Beer and Revolution: The German Anarchist Movement in New York City, 1880–1914. University of Illinois Press. pp. 62, 63. ISBN 978-0-252-03175-5.
- https://books.google.com/books?id=cWt0hISMGrkC&pg=PA221
- https://books.google.com/books?id=LRxCDh9V870C&pg=PA380
"Stauber affair"