- Oliver Cromwell's speeches and letters
- Contemporary accounts of Cromwell's life and career, such as those by Thomas Carlyle, John Morley, and S. R. Gardiner
- The Putney Debates of 1647
- The Agreement of the People of 1649
Secondary Sources
- John Morrill, The Nature of the English Revolution (2000)
- Blair Worden, The Rump Parliament (1974)
- David Underdown, Pride's Purge (1971)
- Austin Woolrych, Commonwealth to Protectorate (1982)
- Mark Kishlansky, The Rise of the New Model Army (1979)