@article{TRSPY_1988_185_a7, author = {A. K. Kerimov}, title = {Sufficient conditions for optimality in an extremal problem with a~free boundary}, journal = {Informatics and Automation}, pages = {87--105}, publisher = {mathdoc}, volume = {185}, year = {1988}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TRSPY_1988_185_a7/} }