@article{MOMA_1977__84_177826,
     author = {Stefan Porubsky},
     title = {On {Exponents} in {Arithmetical} {Semigroups.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {49--54},
     publisher = {mathdoc},
     volume = {84},
     year = {1977},
     zbl = {0368.10036},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1977__84_177826/}
}