@article{MAN_1937__114_159925,
     author = {L. Heffter},
     title = {Das allgemeine {Prinzip} der {Ma{\ss}bestimmung} in der {CayIey-Kleinschen} {Geometrie.}},
     journal = {Mathematische Annalen},
     pages = {432--440},
     publisher = {mathdoc},
     volume = {114},
     year = {1937},
     zbl = {0016.27106},
     url = {http://geodesic.mathdoc.fr/item/MAN_1937__114_159925/}
}