@article{CLTM_1997_1997_1_a25,
     author = {Heinrichs, Wolf-Dieter},
     title = {La condici\'on de densidad y la condici\'on de densidad dual fuerte, mediante operador.},
     journal = {Collectanea mathematica},
     pages = {321-337},
     publisher = {mathdoc},
     volume = {48},
     number = {3},
     year = {1997},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CLTM_1997_1997_1_a25/}
}