1. Boys, S. F., Rajagopal, P.: In: Advances in quantum chemistry, Vol. 2 (ed. P. O. Löwdin) p. 1. New York: Academic Press 1965.
2. Parr, R. G.: Quantum theory of molecular electronic structure. New York: Benjamin 1964. — Mc Weeny, R., Sutcliffe, B. T.: Methods of molecular quantum mechanics. New York: Academic Press 1969.
3. For recent reviews, see: Hirschfelder, J. O. (ed.): Advances in Chemical Physics 12. New York: Wiley 1967. — Margenau, H., Kestner, N. R.: Theory of Intermolecular Forces. New York: Pergamon Press 1971. — Certain, P. R., Bruch, L. W.: In: MTP Intern. Rev. of Sci., Vol. 1, Theoretical Chemistry (ed. W. Byers Brown), p. 113. London: Butterworths 1972.
4. Examples of computational procedures having such characteristic are: Magnasco, V., Dellepiane, G.: Ric. Sci., Parte 2, Sez. A 33, 1173 (1963); Ric. Sci. Parte 2, Sez. A. 34, 275 (1964). — Musso, G. F., Magnasco, V.: J. Phys. B., Atom. Mol. Phys. 4, 1415 (1971); is functions only. — Guidotti, C., Maestro, M., Salvetti, O.: Ric. Sci., Parte 2, Sez. A 35, 1155 (1965). — Guidotti, C., Salvetti, O., Zandomeneghi, M.: Ric. Sci., Parte 2, Sez. A 36, 25 (1966). — Guidotti, C., Maestro, M., Salvetti, O.: Ric. Sci., Parte 2, Sez. A 37, 234. — Guidotti, C., Salvetti, O., Zandomeneghi, M.: Ric. Sci., Parte 2, Sez. A 37, 240 (1967); functions with n < 6, l ⩽ 2. — McLean, A. D., Yoshimine, M.: IBM J. Res. Develop. 12, 206 (1968); linear molecules only. — Wahl, A. C., Land, R. H.: Intern. J. Quantum Chem. 1 S 375 (1967) — Wahl, A. C., Land, R. H.: J. Chem. Phys. 50, 4725 (1969); functions with n ⩽ 8, l⩽ 7.
5. Bonaccorsi, R., Scrocco, E., Tomasi, J.: Theor. Sect. Prog. Report pag. 35. Pisa, Lab. Chim. Quant. CNR 1970; see also: Aspects de la Chimie quantique contemporaine, ed. by R. Daudel and A. Pullman, p. 82. Paris, C. N. R. S. 1971.