@article{CLTM_2006_2006_1_a4,
     author = {Pustylnik, Evgeniy},
     title = {Espacios ultrasim\'etricos de sucesiones en teor{\'\i}a de la aproximaci\'on.},
     journal = {Collectanea mathematica},
     pages = {257-277},
     publisher = {mathdoc},
     volume = {57},
     number = {3},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CLTM_2006_2006_1_a4/}
}