@article{NSJOM_1984__14__a17,
     author = {Bogdanovi\'c Stojan},
     title = {$\sigma$-inverse semigroups},
     journal = {Novi Sad Journal of Mathematics},
     pages = {197-200},
     year = {1984},
     volume = {14},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1984__14__a17/}
}