May, M. S. (2013). Soapbox rebellion: The Hobo Orator union and the free speech fights of the industrial workers of the world, 1909-1916. The University of Alabama Press.

May, Matthew S. Soapbox Rebellion: The Hobo Orator Union and the Free Speech Fights of the Industrial Workers of the World, 1909-1916. Tuscaloosa, Alabama: The University of Alabama Press, 2013.

May, Matthew S. Soapbox Rebellion: The Hobo Orator Union and the Free Speech Fights of the Industrial Workers of the World, 1909-1916. The University of Alabama Press, 2013.