@article{MAN_1967__174_161626,
     author = {K. WOHLFAHRT},
     title = {Zur {Struktur} der rationalen {Modulgruppe.}},
     journal = {Mathematische Annalen},
     pages = {79--99},
     publisher = {mathdoc},
     volume = {174},
     year = {1967},
     zbl = {0157.36101},
     url = {http://geodesic.mathdoc.fr/item/MAN_1967__174_161626/}
}