See John Wesley's letters (ed. by J. Telford, 8 vol., 1831); the standard edition of his journal (ed. by N. Curnock, 4 vol., 1909–16); biographies by D. Bonamy (1933, repr. 1974), V. H. Green (1964, repr. 1987), and D. Marshall (1965); studies by F. Baker (1970), W. J. Warner (1930, repr. 1967), and G. C. Cell (1983); R. L. Maddox and J. E. Vickers, ed., The Cambridge Companion to John Wesley (2009).