00335nam a2200121Ia 4500082001900000100002100019245009400040260002900134300000600163490003400169500000500203700000500208 a515.42bK19.ET aKatok, A. d ed. aErgodic theory and dynamical systems; proceedings of the special year 1979-80, Marylandb aBostonbBirkhauserc1981 a  aProgress in Mathematics v 10 a a