@article{MOMA_1992__114_1_178584,
     author = {Gerd Wegner},
     title = {Relative {Newton} {Numbers.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {149--160},
     publisher = {mathdoc},
     volume = {114},
     number = {1},
     year = {1992},
     zbl = {0765.52016},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1992__114_1_178584/}
}