@article{Masopust_2018,
    doi = {10.1016/j.tcs.2017.11.004},
    url = {https://doi.org/10.1016%2Fj.tcs.2017.11.004},
    year = {2018},
    month = {feb},
    publisher = {Elsevier {BV}},
    volume = {711},
    pages = {109--114},
    author = {Tom{\'{a}}{\v{s}} Masopust},
    title = {Separability by piecewise testable languages is {PTime}-complete},
    journal = {Theoretical Computer Science}
}

@article{Masopust_2018, doi = {10.1016/j.tcs.2017.11.004}, url = {https://doi.org/10.1016%2Fj.tcs.2017.11.004}, year = {2018}, month = {feb}, publisher = {Elsevier {BV}}, volume = {711}, pages = {109--114}, author = {Tom{\'{a}}{\v{s}} Masopust}, title = {Separability by piecewise testable languages is {PTime}-complete}, journal = {Theoretical Computer Science} }