1. Borel, A.: Some finiteness properties of Adele groups over number fields. Publ. Math. IHES16, 1?30 (1963).
2. Lecture Notes Math;C. Delaroche,1972
3. Del Junco, A., andJ. Rosenblatt: Counterexamples in ergodic theory and number theory. Math. Ann.245, 185?197 (1979).
4. Kazhdan, D.: On a connection of the dual space of the group with the structure of its closed subgroups. (In Russian.) Funct. Anal. Prilozhen1, N1, 71?74 (1967). (Math. Rev.35, 288.)
5. Losert, V., andH. Rindler: Almost invariant sets. Bull. London Math. Soc., to appear.