1. Hollinger, H.B.: J. Chem. Phys.36, 3208 (1962)
2. Kirkwood, J.B.: J. Chem. Phys.14, 180 (1946);15, 72 (1947)
3. Bogolyubov, N.N.: J. Phys. (Moscow)10, 256 (1946)
4. Uhlenbeck, G., Ford, G.: Lectures in Statistical Mechanics. Rhode Island, USA 1963
5. Goldberger, M., Watson, K.: Collision Theory. New York-London-Sydney: Wiley 1964