1. Entropy and the fundamental group;Bowen;Springer LNM,1978
2. Entropy for group endomorphisms and homogeneous spaces;Bowen;Trans. Am. Math. Soc.,1971
3. The ergodic theory of axiom A flows;Bowen;Inv. Math.,1975
4. Entropy and exponential growth of π1 in dimension two;Franks;MSRI preprint,1984