@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/