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@article{PIM_1966_N_S_06_20_a6, author = {L. Collatz}, title = {Rationalle {Trigonometrische} {Tschebyscheff-Approximation} {In} {Zwei} {Variablen}}, journal = {Publications de l'Institut Math\'ematique}, pages = {57 }, publisher = {mathdoc}, volume = {_N_S_06}, number = {20}, year = {1966}, url = {http://geodesic.mathdoc.fr/item/PIM_1966_N_S_06_20_a6/} }
L. Collatz. Rationalle Trigonometrische Tschebyscheff-Approximation In Zwei Variablen. Publications de l'Institut Mathématique, _N_S_06 (1966) no. 20, p. 57 . http://geodesic.mathdoc.fr/item/PIM_1966_N_S_06_20_a6/