Johnston, R. D. (2006). The radical middle class: Populist democracy and the question of capitalism in progressive era Portland, Oregon. Princeton University Press.

Johnston, Robert D. The Radical Middle Class: Populist Democracy and the Question of Capitalism in Progressive Era Portland, Oregon. Princeton, New Jersey ; Oxfordshire, England: Princeton University Press, 2006.

Johnston, Robert D. The Radical Middle Class: Populist Democracy and the Question of Capitalism in Progressive Era Portland, Oregon. Princeton University Press, 2006.