@article{MS2_1982__50_166781, author = {Jorgen Hoffmann-Jorgensen}, title = {A general }, journal = {Mathematica Scandinavica}, pages = {55--65}, publisher = {mathdoc}, volume = {50}, year = {1982}, zbl = {0494.54013}, url = {http://geodesic.mathdoc.fr/item/MS2_1982__50_166781/} }