@article{SF_1975__10_134121,
     author = {M. Petrich},
     title = {Correction to },
     journal = {Semigroup forum},
     pages = {277--279},
     publisher = {mathdoc},
     volume = {10},
     year = {1975},
     zbl = {0365.20067},
     url = {http://geodesic.mathdoc.fr/item/SF_1975__10_134121/}
}