@article{ELMA_1978__33_141207,
     author = {H. Bieri},
     title = {Extremaleigenschaften rotationssysmmetrischer {Kegelst\"umpfe} im gew\"ohnlichen {Raum.} (1. {Teil).}},
     journal = {Elemente der Mathematik},
     pages = {7--14},
     publisher = {mathdoc},
     volume = {33},
     year = {1978},
     zbl = {0379.52008},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1978__33_141207/}
}