Reference Label	Details
Ames 1976	D. L. Ames and D. W. Turner, Proc. Roy. Soc. London A 348, 175-186 (1976) Photoelectron Spectroscopic Studies of Dinitrogen Tetroxide and Dinitrogen Pentoxide
Lloyd 1975	D. R. Lloyd, P. J. Roberts, and I. H. Hillier, J. Chem. Soc. Faraday Trans. II 71, 496-503 (1975) Electronic Structure of Nitric Acid Studied by Photoelectron Spectroscopy and Molecular Orbital Calculation