TY  - JOUR
AU  - Wilhelm Magnus
TI  - Rings of Fricke Characters and Automorphism Groups of Free Groups.
JO  - Mathematische Zeitschrift
PY  - 1980
SP  - 91
EP  - 104
VL  - 170
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZ_1980__170_172903/
ID  - MZ_1980__170_172903
ER  -