@article{RRACEFN_1997_1997_1_a7,
     author = {Criado, Francisco and  Meladze, Gamlet and  Odisehlidze, Nana},
     title = {An optimal control problem for {Helmholtz} equation with non-local boundary conditions and quadratic funtional},
     journal = {Revista de la Real Academia de Ciencias Exactas, F{\'\i}sicas y Naturales },
     pages = {65-69},
     publisher = {mathdoc},
     volume = {91},
     number = {1},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RRACEFN_1997_1997_1_a7/}
}