@article{ELMA_1990__45_6_141486,
     author = {D. Laugwitz},
     title = {Kettenwurzeln und {Kettenoperationen.}},
     journal = {Elemente der Mathematik},
     pages = {89--98},
     publisher = {mathdoc},
     volume = {45},
     number = {6},
     year = {1990},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1990__45_6_141486/}
}