@article{JDM_1973__75_146625,
     author = {Pl. Kannappan},
     title = {Groupoids and {Groups.}},
     journal = {Jahresbericht der Deutschen Mathematiker-Vereinigung},
     pages = {94--100},
     publisher = {mathdoc},
     volume = {75},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JDM_1973__75_146625/}
}