@article{TM2_2018_XXI_1_a4,
     author = {Lenni Haapasalo},
     title = {Bernd {Zimmermann} {(Obituary)}},
     journal = {The Teaching of Mathematics},
     pages = {53 },
     year = {2018},
     volume = {XXI},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/TM2_2018_XXI_1_a4/}
}