@article{JDM_1959__61_146453,
     author = {Hans Wittich and Rolf Nevanlinna},
     title = {Egon {Ulrich} in memoriam.},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {57--65},
     publisher = {mathdoc},
     volume = {61},
     year = {1959},
     zbl = {0082.01214},
     url = {http://geodesic.mathdoc.fr/item/JDM_1959__61_146453/}
}