@article{IM_1992__110_2_144046,
     author = {Walter D. Neumann},
     title = {The fixed group of an automorphism of a word hyperbolic group is rational.},
     journal = {Inventiones mathematicae},
     pages = {147--150},
     publisher = {mathdoc},
     volume = {110},
     number = {2},
     year = {1992},
     zbl = {0793.20033},
     url = {http://geodesic.mathdoc.fr/item/IM_1992__110_2_144046/}
}