Anstey, Sandra, ed. Critical Writings on R. S. Thomas. Rev. ed. Chester Springs, Pa.: Dufour Editions, 1992. A collection of essays on Thomas’s poetry dating from 1952 to 1991, including two by A. M. Allchin, and one by Peter Abbs, a fellow Anglo-Welsh poet. The essays are taken from Anglo-Welsh literary journals.
Brown, Tony. R. S. Thomas. Cardiff: University of Wales Press, 2003. This introductory work, part of the Writers of Wales series, deals with biography and critical assessments and analyses.
Davis, William V. R. S. Thomas: Poetry and Theology. Baylor, Texas: Baylor University Press, 2007. This is an introductory work on Thomas’s poetry, especially his more obviously religious poetry.
McGill, William J. Poets’ Meeting: George Herbert, R. S. Thomas, and the Argument with God. Jefferson, N.C.: McFarland, 2003. This compares the two Anglican priest-poets and the way they address God, either from faith or doubt.
Morgan, Christopher. R. S. Thomas: Identity, Environment, Deity. New York: Manchester University Press, 2003. Deals with common themes in Thomas’s volumes of verse, especially those that focus on the philosophical and practical aspects of science and technology (“machine”).
Rogers, Byron. The Man Who Went into the West: The Life of R. S. Thomas. London: Aurum Press, 2006. This is the authorized biography of Thomas, supported with a major research grant from the Welsh Books Council. It includes extensive interviews with Thomas’s son and many others, and the finding of extensive correspondence and documentation not hitherto available.