@article{KYB_1992_28_1_a0,
     author = {Kramosil, Ivan},
     title = {An alternative approach to rough sets},
     journal = {Kybernetika},
     pages = {1--25},
     year = {1992},
     volume = {28},
     number = {1},
     mrnumber = {1159871},
     zbl = {0749.04006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_1992_28_1_a0/}
}