@article{10_4171_ggd_667,
     author = {Ara Basmajian and Robert Suzzi Valli},
     title = {Combinatorial growth in the modular group},
     journal = {Groups, geometry, and dynamics},
     pages = {683--703},
     year = {2022},
     volume = {16},
     number = {2},
     doi = {10.4171/ggd/667},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/667/}
}