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@article{DAN_1961_137_4_a1, author = {I. V. Gel'man}, title = {Equivalence of some unbounded operators in {Banach} space}, journal = {Doklady Akademii Nauk}, pages = {764--767}, publisher = {mathdoc}, volume = {137}, number = {4}, year = {1961}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1961_137_4_a1/} }
I. V. Gel'man. Equivalence of some unbounded operators in Banach space. Doklady Akademii Nauk, Tome 137 (1961) no. 4, pp. 764-767. http://geodesic.mathdoc.fr/item/DAN_1961_137_4_a1/