@article{MAN_1974__212_182743,
     author = {Morris Newman},
     title = {Formulas and {Multiplicative} {Relationships} for the {Parameters} of {Subgroups} of the {Modular} {Group.}},
     journal = {Mathematische Annalen},
     pages = {173--182},
     publisher = {mathdoc},
     volume = {212},
     year = {1974},
     zbl = {0278.10024},
     url = {http://geodesic.mathdoc.fr/item/MAN_1974__212_182743/}
}