@article{PIM_1994_N_S_56_70_a4,
     author = {Miroslav Plo\v{s}\v{c}ica},
     title = {Graphical {Compositions} and {Weak} {Congruences}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {34 },
     publisher = {mathdoc},
     volume = {_N_S_56},
     number = {70},
     year = {1994},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PIM_1994_N_S_56_70_a4/}
}