1. Lanford, O. E.: Commun. Math. Phys.9, 169–191 (1968).
2. Ruelle, D.: J. Math. Phys.8, 1657 (1967).
3. Robinson, D. W., andD. Ruelle: Commun. Math. Phys.5, 288 (1967).
4. Halmos, P. R.: Measure theory, Section 52, Theorem G. New York: Van Nostrand 1950.
5. Dunford, N., andJ. T. Schwartz: Linear operators, Part I, Corollary IV.8.11 and Theorem V.6.1. New York: Interscience 1958.