1. Valence and The Structure of Atoms and Molecules, Chemical Catalog, New York, 1923.
2. The Lewis Acid-Base Concepts, Wiley-Interscience, New York, 1980;
3. The Lewis acid-base definitions: a status report
4. In 1923 Lewis stated that “… with complete generality we may say that a basic substance is one which has a lone pair of electrons which may be used to complete the stable group of another atom and that an acid substance is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms. In other words, the basic substance furnishes a pair of electrons for a chemical bond; the acid substance accepts such a pair.” Valence and The Structure of Atoms and Molecules, Chemical Catalog, New York, 1923, pp. 141–142.
5. The Lewis acid-base definitions: a status report