@article{MOMA_1966__70_177331,
     author = {H. Engels and S. Filippi},
     title = {Neue {S\"atze} und {Ergebnisse} zur numerischen {Differentiation.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {193--211},
     publisher = {mathdoc},
     volume = {70},
     year = {1966},
     zbl = {0146.13904},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1966__70_177331/}
}