@article{SF_1997__54_2_135524,
     author = {S. Duplij},
     title = {Some abstract properties of semigroups appearing in superconformal theories.},
     journal = {Semigroup forum},
     pages = {253--260},
     publisher = {mathdoc},
     volume = {54},
     number = {2},
     year = {1997},
     zbl = {0879.58009},
     url = {http://geodesic.mathdoc.fr/item/SF_1997__54_2_135524/}
}