@article{NUMA_1972__19_132164,
     author = {P. Forster},
     title = {Die diskrete {Greensche} {Funktion} und {Fehlerabsch\"atzungen} zum {Galerkin-Verfahren.}},
     journal = {Numerische Mathematik},
     pages = {407--418},
     publisher = {mathdoc},
     volume = {19},
     year = {1972},
     zbl = {0248.65050},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1972__19_132164/}
}