1. G. Herzberg:Molecular Spectra and Molecular Structure. II.Infrared and Ruman Spectra of Polyatomic Molecules (New York, 1945).
2. F. Halverson:Rev. Mod. Phys.,19, 81 (1947).
3. A. Langseth etR. C. Lord:Banish Academy, Math.-fys. Medd.,16, 6 (1938).
4. C. K. Ingold et al.: Structure of benzene: Parts. I-IX,Journ. Am. Chem. Soc., pp. 912–1214 (1936);
5. Part X,Journ. Am. Chem. Soc., p. 1728 (1937);