@article{ELMA_1991__46_2_141505,
     author = {H. Martini and G. Geise},
     title = {Klassische {Beleuchtungsgeometrie} im {Ed} (d...2). {I.} {Bekannte} {Kurvenklassen} in der {Beleuchtungsgeometrie} des {Ed} (d...2).},
     journal = {Elemente der Mathematik},
     pages = {73--78},
     publisher = {mathdoc},
     volume = {46},
     number = {2},
     year = {1991},
     zbl = {0682.53004},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1991__46_2_141505/}
}