@article{dmtcs:490,
    title      = {New decidable upper bound of the second level in the Straubing-Therien concatenation hierarchy of star-free languages},
    author     = {Jorge Almeida and Ondrej Klima},
    url        = {https://dmtcs.episciences.org/490},
    doi        = {10.46298/dmtcs.490},
    journal    = {Discrete Mathematics \& Theoretical Computer Science},
    issn       = {1365-8050},
    volume     = {Vol. 12 no. 4},
    eid        = 1,
    year       = {2010},
    month      = {Jan},
    keywords   = {formal languages, regular languages, concatenation hierarchies, level two, star-free languages, [INFO.INFO-DM] Computer Science [cs]/Discrete Mathematics [cs.DM]},
    language   = {English},
}