@article{ELMA_1954__9_140607,
     author = {K.F. Moppert},
     title = {\"Uber das {Rechnen} mit {Operatoren.}},
     journal = {Elemente der Mathematik},
     pages = {73--76},
     publisher = {mathdoc},
     volume = {9},
     year = {1954},
     zbl = {0055.10802},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1954__9_140607/}
}