@article{CM_1984__52_2_231_0,
     author = {Im Hof, Hans-Christoph},
     title = {Ellipsoids and hyperboloids with infinite foci},
     journal = {Compositio Mathematica},
     pages = {231--244},
     publisher = {Martinus Nijhoff Publishers},
     volume = {52},
     number = {2},
     year = {1984},
     mrnumber = {750359},
     zbl = {0544.53034},
     language = {en},
     url = {http://www.numdam.org/item/CM_1984__52_2_231_0/}
}