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@article{MOMA_1961__65_177116, author = {Ulrich Christian}, title = {On {Certain} {Factors} of {Automorphy} for the {Modular} {Group} of {Degree} n.}, journal = {Monatshefte f\"ur Mathematik}, pages = {82--87}, publisher = {mathdoc}, volume = {65}, year = {1961}, zbl = {0095.06403}, url = {http://geodesic.mathdoc.fr/item/MOMA_1961__65_177116/} }
Ulrich Christian. On Certain Factors of Automorphy for the Modular Group of Degree n.. Monatshefte für Mathematik, Tome 65 (1961), pp. 82-87. http://geodesic.mathdoc.fr/item/MOMA_1961__65_177116/