@article{10_4064_cm_55_1_5_9,
     author = {Miroslav Kratko},
     title = {On characteristic sets of a system of equivalence relations},
     journal = {Colloquium Mathematicum},
     pages = {5--9},
     publisher = {mathdoc},
     volume = {55},
     number = {1},
     year = {1987},
     doi = {10.4064/cm-55-1-5-9},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-55-1-5-9/}
}