@article{EXMATH_1988_1988_1_a13,
     author = {Fern\'andez Castillo, Jes\'us M.},
     title = {El problema de la suma para espacios de {Hilbert}},
     journal = {Extracta mathematicae},
     pages = {26-27},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1988},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMATH_1988_1988_1_a13/}
}