@article{PIM_1973_N_S_15_29_a1,
     author = {Branka P. Alimpi\'c},
     title = {Ballanced {Laws} {On} {GD-Groupoids}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {21 },
     publisher = {mathdoc},
     volume = {_N_S_15},
     number = {29},
     year = {1973},
     url = {http://geodesic.mathdoc.fr/item/PIM_1973_N_S_15_29_a1/}
}