@article{DMGAA_2002_22_2_a6,
     author = {Radeleczki, S\'andor},
     title = {Classification systems and their lattice},
     journal = {Discussiones Mathematicae. General Algebra and Applications},
     pages = {167--181},
     publisher = {mathdoc},
     volume = {22},
     number = {2},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGAA_2002_22_2_a6/}
}