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@article{PIM_1968_N_S_08_22_a17, author = {Z. Dar\'oczy}, title = {\"Uber {Eine} {Fuktionalgleichung} {Im} {Hilbertraum}}, journal = {Publications de l'Institut Math\'ematique}, pages = {121 }, publisher = {mathdoc}, volume = {_N_S_08}, number = {22}, year = {1968}, url = {http://geodesic.mathdoc.fr/item/PIM_1968_N_S_08_22_a17/} }
Z. Daróczy. Über Eine Fuktionalgleichung Im Hilbertraum. Publications de l'Institut Mathématique, _N_S_08 (1968) no. 22, p. 121 . http://geodesic.mathdoc.fr/item/PIM_1968_N_S_08_22_a17/