@article{EJDE_1993__1993_4_a0,
     author = {Groetsch,  C.W. and Scherzer,  O.},
     title = {Optimal order of convergence for stable evaluation of differential operators},
     journal = {Electronic journal of differential equations},
     year = {1993},
     volume = {1993},
     number = {4},
     zbl = {0788.47010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_1993__1993_4_a0/}
}