Reference Label	Details
Moore 1970	C. E. Moore, "Ionization Potentials and Ionization Limits Derived from Analyses of Optical Spectra", NSRDS-NBS 34, National Bureau of Standards: Washington, DC 1970
Bromander 1967	J. Bromander, B. Johansson, and K. Bockasten J. Opt. Soc. Amer. 57, 1158-1159 (1967) Spectra of O IV and O V