1. For reviews of semiempirical theory applied to the organic chemistry see Molecular Orbital Theory for Organic Chemists (John Wiley & Sons, Inc., New York, 1961);
2. The Theory of the Electronic Spectra of Organic Molecules (John Wiley & Sons, Inc., New York, 1963);
3. Quantum Chemistry, Vol. 1 (Allyn and Bacon, Boston, 1970);
4. The Molecular Orbital Theory of Organic Chemistry (McGraw-Hill, New York, 1969);
5. and Approximate Molecular Orbital Theory (McGraw-Hill, New York, 1970);