@article{MS2_1984__54_166889,
     author = {Christian Berg},
     title = {Semi-groupes de moments.},
     journal = {Mathematica Scandinavica},
     pages = {177--182},
     year = {1984},
     volume = {54},
     zbl = {0528.43004},
     url = {http://geodesic.mathdoc.fr/item/MS2_1984__54_166889/}
}