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@article{IVM_1978_3_a1, author = {D. L. Berman}, title = {An averaging operator}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {10--14}, publisher = {mathdoc}, number = {3}, year = {1978}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1978_3_a1/} }
D. L. Berman. An averaging operator. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 3 (1978), pp. 10-14. http://geodesic.mathdoc.fr/item/IVM_1978_3_a1/