- D. Seckler, "Folklore of the Banal." Art in America 50, 1952, illustrated in the catalogue p. 58
- A. C. Carr, "The Reminiscences of Robert Indiana", New York, November 1965. Arthur C. Carr papers; Rare Book and Manuscript Library, Columbia University Library, described in the catalogue p. 76, under the title "Tintinnabulation"
- J.W. Mc Courbay and R. Indiana, "Robert Indiana", Philadelphia: Institute of Contemporary Art and Falcon Press, 1968, illustrated in the catalogue pp. 30 and 31 under the title "Triangle"
- W.B. Bell, "The Rudolph Collection", Berkshire Eagle (Pittsfield, Mass.), 23 October 1971, illustrated in the catalogue under no. 3 p. 5
- W. Katz, "Robert Indiana" Currant 1 (December 1975 - January 1976), illustrated in the catalogue p. 48.
- R.L.B. Tobin, W Katz. and D.B. Goodall, "Robert Indiana", Austin: University of Texas, 1977, illustrated in the catalogue p. 21
- C. J. Weinhardt, "Jr. Robert Indiana", New York: Harry N. Abrams, 1990. Monograph, described in the catalogue pp. 26 and 113 and illustrated p. 29
- Ryan, S.E., "Robert Indiana: Figures of Speech", New Haven: Yale University Press, 2000, p. 154, illustrated in the catalogue under no. 4.44 p. 150
- Wilmerding, John, Joachim Pissarro, and Robert Pincus-Witten, "Robert Indiana", New York, Rizzoli international publications, 2006, illustrated in the catalogue p. 160
- Simon Salama-Caro, "The Robert Indiana Catalogue Raisonne", RI Catalogue Raisonné LLC. (online catalogue)