Gunther Seitz; Peter Imming (1992). "Oxocarbons and pseudooxocarbons". Chemical Reviews. 92 (6): 1227–1260. doi:10.1021/cr00014a004.
Person, Willis B.; Williams, Dale G. (1957). "Infrared spectra and the structures of leuconic acid and triquinoyl". J. Phys. Chem. 61 (7): 1017–1018. doi:10.1021/j150553a047.