.................
Conquest of Violence "The Gandhian Philosophy of Conflict", by Joan V. Bondurant, Princeton University Press, Prinston NJ, 1958.
Gandhi, Prisoner of Hope, by Judith M. Brown, Yale University Press, New Haven and London, 1989.
The Life of Mahatma Gandhi, by Louis Fischer, Harper & Row, NY, 1950.
An Autobiography, The Story of My Experiments with Truth by Mohandas K. Gandhi, Beacon Press, Boston, 1957.
The Kingdom Of God and Peace Essays by Leo Tolstoy, Oxford, 1893, 1894.
The Bible, especially The New Testament
Zen Flesh Zen Bones, "A collection of Zen and pre-Zen writings", Compiled by Reps and Nyogen Senzaki, Tuttle Publishing, Boston, 1957.
Check out...
Mark Shepard's Nonviolent Bookshelf