@article{JDM_1967__69_146551,
     author = {Hans Bonnet},
     title = {Geleitwort},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {75--76},
     publisher = {mathdoc},
     volume = {69},
     year = {1967},
     url = {http://geodesic.mathdoc.fr/item/JDM_1967__69_146551/}
}