@article{CLTM_1973_1973_1_a3,
     author = {Ben{\'\i}tez, Carlos},
     title = {Caracterizaci\'on de aproximaciones \'optimas en espacios producto.},
     journal = {Collectanea mathematica},
     pages = {19-26},
     publisher = {mathdoc},
     volume = {24},
     number = {1},
     year = {1973},
     language = {es},
     url = {http://geodesic.mathdoc.fr/item/CLTM_1973_1973_1_a3/}
}