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@article{IVM_1962_2_a20, author = {E. S. Chichkin}, title = {A theorem on a differential inequality for multi-point boundary-value problems}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {170--179}, publisher = {mathdoc}, number = {2}, year = {1962}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1962_2_a20/} }
E. S. Chichkin. A theorem on a differential inequality for multi-point boundary-value problems. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 2 (1962), pp. 170-179. http://geodesic.mathdoc.fr/item/IVM_1962_2_a20/