@article{10_4064_fm_88_2_117_120,
     author = {Ahmad Shafaat},
     title = {Boolean groupoids},
     journal = {Fundamenta Mathematicae},
     pages = {117--120},
     publisher = {mathdoc},
     volume = {88},
     number = {2},
     year = {1975},
     doi = {10.4064/fm-88-2-117-120},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-88-2-117-120/}
}