1. Roothaan CCJ (1952) Rev Mod Phys 22:571
2. Hall GG 1(51) Proc R Soc London A 205:541
3. Pople JA, Nesbet RK (1954) J Chem Phys 22:571
4. The popular Gaussian series of programs by Pople JA and his co-workers is, for example, based on the UHF theory for open-shell SCF for M�ller-Plesset Perturbation Theory. Binkley JS, Frisch MJ, DeFrees DJ, Raghavachari K, Whitesides HB, Schlegel HB, Fluder EM, Pople JA, Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pa
5. L�wdin PO (1959) Adv Chem Phys 2:207