@article{10_1017_S0017089511000188,
     author = {DOLINKA, IGOR},
     title = {ON {FREE} {SPECTRA} {OF} {LOCALLY} {TESTABLE} {SEMIGROUP} {VARIETIES}},
     journal = {Glasgow mathematical journal},
     pages = {623--629},
     year = {2011},
     volume = {53},
     number = {3},
     doi = {10.1017/S0017089511000188},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089511000188/}
}