@article{Ibarra_2013,
    doi = {10.1016/j.tcs.2013.07.025},
    url = {https://doi.org/10.1016%2Fj.tcs.2013.07.025},
    year = {2013},
    month = {aug},
    publisher = {Elsevier {BV}},
    volume = {501},
    pages = {11--19},
    author = {Oscar H. Ibarra and Shinnosuke Seki},
    title = {On the open problem of Ginsburg concerning semilinear sets and related problems},
    journal = {Theoretical Computer Science}
}

@article{Ibarra_2013, doi = {10.1016/j.tcs.2013.07.025}, url = {https://doi.org/10.1016%2Fj.tcs.2013.07.025}, year = {2013}, month = {aug}, publisher = {Elsevier {BV}}, volume = {501}, pages = {11--19}, author = {Oscar H. Ibarra and Shinnosuke Seki}, title = {On the open problem of Ginsburg concerning semilinear sets and related problems}, journal = {Theoretical Computer Science} }