@article{EXMATH_1990_1990_1_a39,
     author = {Acosta, Mar{\'\i}a D.},
     title = {Espacios {CL} y operadores que alcanzan el radio num\'erico.},
     journal = {Extracta mathematicae},
     pages = {138-140},
     publisher = {mathdoc},
     volume = {5},
     number = {3},
     year = {1990},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMATH_1990_1990_1_a39/}
}