@article{STO_1981_1981_1_a0,
     author = {Esteva, Francesc},
     title = {Negaciones en la teor{\'\i}a de conjuntos difusos.},
     journal = {Stochastica},
     pages = {33-44},
     publisher = {mathdoc},
     volume = {5},
     number = {1},
     year = {1981},
     language = {es},
     url = {http://geodesic.mathdoc.fr/item/STO_1981_1981_1_a0/}
}