@article{GDZPPN001164740,
title = {An Error Formula for Numerical Differentiation.},
journal = {Numerische Mathematik},
volume = {5},
year = {1963},
pages = {439-442},
zbl = {0123.12105},
url = {http://dml.mathdoc.fr/item/GDZPPN001164740}
}
KRANZER, H.C. An Error Formula for Numerical Differentiation.. Numerische Mathematik, Tome 5 (1963) pp. 439-442. http://gdmltest.u-ga.fr/item/GDZPPN001164740/