Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MAN_1960__140_160778, author = {P.L. Butzer and H.G. TILLMANN}, title = {Approximation {Theorems} for {Semi-Groups} of {Bounded} {Linear} {Transformations.}}, journal = {Mathematische Annalen}, pages = {256--262}, publisher = {mathdoc}, volume = {140}, year = {1960}, zbl = {0094.30602}, url = {http://geodesic.mathdoc.fr/item/MAN_1960__140_160778/} }
P.L. Butzer; H.G. TILLMANN. Approximation Theorems for Semi-Groups of Bounded Linear Transformations.. Mathematische Annalen, Tome 140 (1960), pp. 256-262. http://geodesic.mathdoc.fr/item/MAN_1960__140_160778/