@article{Schmid_2016,
    doi = {10.1016/j.ic.2016.02.003},
    url = {https://doi.org/10.1016%2Fj.ic.2016.02.003},
    year = {2016},
    month = {aug},
    publisher = {Elsevier {BV}},
    volume = {249},
    pages = {1--17},
    author = {Markus L. Schmid},
    title = {Characterising {REGEX} languages by regular languages equipped with factor-referencing},
    journal = {Information and Computation}
}

@article{Schmid_2016, doi = {10.1016/j.ic.2016.02.003}, url = {https://doi.org/10.1016%2Fj.ic.2016.02.003}, year = {2016}, month = {aug}, publisher = {Elsevier {BV}}, volume = {249}, pages = {1--17}, author = {Markus L. Schmid}, title = {Characterising {REGEX} languages by regular languages equipped with factor-referencing}, journal = {Information and Computation} }