@article{MS2_1975__37_166424,
     author = {Ralph Fr\"oberg},
     title = {Determination of a class of {Poincar\'e} series.},
     journal = {Mathematica Scandinavica},
     pages = {29--39},
     publisher = {mathdoc},
     volume = {37},
     year = {1975},
     zbl = {0318.13027},
     url = {http://geodesic.mathdoc.fr/item/MS2_1975__37_166424/}
}