@article{MZ_1936__40_168626,
     author = {H. Beck},
     title = {\"Uber {Ternionen} in der {Geometrie}},
     journal = {Mathematische Zeitschrift},
     pages = {509--520},
     publisher = {mathdoc},
     volume = {40},
     year = {1936},
     zbl = {0012.36703},
     url = {http://geodesic.mathdoc.fr/item/MZ_1936__40_168626/}
}