Ward, Charles. “The Use of Hymn Tunes as an Expression of ‘Substance’ and ‘Manner’ in the Music of Charles E. Ives.” Master’s Essay, University of Texas at Austin, 1969.
Dujmic, Dunja. “The Musical Transcendentalism of Charles Ives.” International Review of the Aesthetics and Sociology of Music Vol. 2, No. 1 (June, 1971).