@article{10_2307_2661355,
     author = {Marcus du Sautoy and Fritz Grunewald},
     title = {Analytic properties of zeta functions and subgroup growth},
     journal = {Annals of mathematics},
     year = {2000},
     volume = {152},
     number = {3},
     doi = {10.2307/2661355},
     zbl = {1006.11051},
     url = {http://geodesic.mathdoc.fr/articles/10.2307/2661355/}
}