@article{MZ_1991__206_1_174250,
     author = {Konrad Schm\"udgen},
     title = {Non-commutative moment problems.},
     journal = {Mathematische Zeitschrift},
     pages = {623--650},
     publisher = {mathdoc},
     volume = {206},
     number = {1},
     year = {1991},
     zbl = {0712.22010},
     url = {http://geodesic.mathdoc.fr/item/MZ_1991__206_1_174250/}
}