TY  - JOUR
AU  - Helfrich, Hans-Peter
TI  - Simultaneous approximation in negative norms of arbitrary order
JO  - ESAIM: Mathematical Modelling and Numerical Analysis 
PY  - 1981
SP  - 231
EP  - 235
VL  - 15
IS  - 3
PB  - Centrale des revues, Dunod-Gauthier-Villars
PP  - Montreuil
UR  - https://geodesic-test.mathdoc.fr/item/M2AN_1981__15_3_231_0/
LA  - en
ID  - M2AN_1981__15_3_231_0
ER  -