@article{IM_1992__110_2_144042,
     author = {Erling Stormer},
     title = {Entropy of some automorphisms of the {II1-factor} of the free group in infinite number of generators.},
     journal = {Inventiones mathematicae},
     pages = {63--74},
     year = {1992},
     volume = {110},
     number = {2},
     zbl = {0807.46079},
     url = {http://geodesic.mathdoc.fr/item/IM_1992__110_2_144042/}
}