@article{10_4064_cm_80_1_97_105, author = {Ulrich Albrecht and H. Goeters}, title = {Strong ${\cal S}$-groups}, journal = {Colloquium Mathematicum}, pages = {97--105}, publisher = {mathdoc}, volume = {80}, number = {1}, year = {1999}, doi = {10.4064/cm-80-1-97-105}, language = {en}, url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-80-1-97-105/} }