@article{10_14708_ma_v8i16_1466,
     author = {Walenty Ostasiewicz},
     title = {On fuzzy sets},
     journal = {Mathematica Applicanda},
     pages = { 5--26},
     publisher = {mathdoc},
     volume = {8},
     number = {16},
     year = {1980},
     doi = {10.14708/ma.v8i16.1466},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/ma.v8i16.1466/}
}