@article{MASLO_1967__17_3_a1,
     author = {Hrmov\'a, Ren\'ata},
     title = {Relative ideals in semigroups},
     journal = {Mathematica slovaca},
     pages = {206--223},
     publisher = {mathdoc},
     volume = {17},
     number = {3},
     year = {1967},
     mrnumber = {0223471},
     zbl = {0189.30403},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MASLO_1967__17_3_a1/}
}