@article{10_21136_CMJ_1991_102478,
     author = {Radelecki, S\'andor},
     title = {Compatible tolerances on groupoids},
     journal = {Czechoslovak Mathematical Journal},
     pages = {436--445},
     publisher = {mathdoc},
     volume = {41},
     number = {3},
     year = {1991},
     doi = {10.21136/CMJ.1991.102478},
     mrnumber = {1117797},
     zbl = {0768.20027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1991.102478/}
}