@article{10_1017_S2040618500035358,
     author = {Rankin, R. A.},
     title = {Isomorphic congruence groups and {Hecke} operators},
     journal = {Glasgow mathematical journal},
     pages = {168--168},
     year = {1966},
     volume = {7},
     number = {3},
     doi = {10.1017/S2040618500035358},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S2040618500035358/}
}