@article{10_1017_S0017089500006133,
     author = {Macbeath, A. M.},
     title = {Generic {Dirichlet} polygons and the modular group},
     journal = {Glasgow mathematical journal},
     pages = {129--141},
     year = {1985},
     volume = {26},
     doi = {10.1017/S0017089500006133},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500006133/}
}