@article{IM_1986__86_143401, author = {Y. Ihara}, title = {On {Galois} representations arising from towers of coverings of {P1} ... .}, journal = {Inventiones mathematicae}, pages = {427--460}, publisher = {mathdoc}, volume = {86}, year = {1986}, zbl = {0585.14020}, url = {http://geodesic.mathdoc.fr/item/IM_1986__86_143401/} }