@article{10_21136_CMJ_1975_101308,
     author = {Zelinka, Bohdan},
     title = {Tolerance in algebraic structures. {II}},
     journal = {Czechoslovak Mathematical Journal},
     pages = {175--178},
     publisher = {mathdoc},
     volume = {25},
     number = {2},
     year = {1975},
     doi = {10.21136/CMJ.1975.101308},
     mrnumber = {0457323},
     zbl = {0316.08001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1975.101308/}
}