@article{MV_1970_22_3_a19,
     author = {S. Lajos},
     title = {A characterezation of regular duo semigroups},
     journal = {Matemati\v{c}ki vesnik},
     pages = {401 },
     year = {1970},
     volume = {22},
     number = {3},
     url = {http://geodesic.mathdoc.fr/item/MV_1970_22_3_a19/}
}