1. The results are taken from the Ph. D. thesis by The Pennsylvania State University, University Park, 1995, and
2. the dissertation by University of Würzburg, 1998.
3. , , Annulenes, Benzo-, Hetero-, Homo-Derivatives, and their Valence Isomers, 1st ed., CRC Press, Boca Raton, Florida, USA, 1987, vol. 1.
4. , Hydrogen Bonding, 1st ed. Marcel Dekker, New York, 1974;