@article{EXMATH_1991_1991_1_a16,
     author = {Sim\^oes, Marilda A.},
     title = {Sobre las clases {S\ensuremath{\varphi}} de {Schatten.}},
     journal = {Extracta mathematicae},
     pages = {52-54},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMATH_1991_1991_1_a16/}
}