%0 Journal Article %A Nobuhiko Ishida %T Generators and equations for modular function fields of principal congruence subgroups %J Acta Arithmetica %D 1998 %P 197-207 %V 85 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/aa-85-3-197-207/ %R 10.4064/aa-85-3-197-207 %G en %F 10_4064_aa_85_3_197_207