Roberts, John D.; Streitwieser, Andrew Jr.; Regan, Clare M. (1952). “Small-Ring Compounds. X. Molecular Orbital Calculations of Properties of Some Small-Ring Hydrocarbons and Free Radicals”. 《J. Am. Chem. Soc.》 74 (18): 4579–82. doi:10.1021/ja01138a038.