Theem, Rolf H. W. Peter Nikitich Tkachev: A Study in Revolutionary Theory unpublished dissertation, 1964. Subject: Tkachev, Peter Nikitich. Subject: Indiana University - Theses and Dissertations, MGEN M5200. General Collection, GEN. University of Notre Dame Archives. https://archivesspace.library.nd.edu/repositories/2/archival_objects/1099616 Accessed October 19, 2024.