1. Friedel, R. A., and M. Orobin: Ultraviolet Spectra of Aromatic Compounds, 579 spectra. New York City, U.S.A.: John Wiley and Sons.
2. Mellon, M. G.: Analytical Absorption Spectroscopy, 618 p., New York City, U.S.A., John Wiley and Sons.
3. Kaye, W. I.: Spectrochimica Acta, Part I — 6, 257 (1954)
4. Kaye, W. I.: Ibid. Part II — 7, 181 (1955).
5. Mees, F. G.: Stevens, unpublished work.