1. N. N. Greenwood , in Comprehensive Inorganic Chemistry, Pergamon, Oxford, 1973, vol. 1, p. 666.
2. G. N. Lewis , Valence and the Structures of Atoms and Molecules, The Chemical Catalog Company Inc., New York, 1923, p. 98.
3. Reaction of BF3 with NH3: Microwave spectrum of BF2NH2