@article{SF_1986__35_134880,
     author = {V.S. Krishnan and M. Levitan},
     title = {Regular involution groupoids revisited.},
     journal = {Semigroup forum},
     pages = {353--368},
     publisher = {mathdoc},
     volume = {35},
     year = {1986},
     zbl = {0624.20038},
     url = {http://geodesic.mathdoc.fr/item/SF_1986__35_134880/}
}