@article{Geffert_2007,
    doi = {10.1016/j.ic.2007.07.001},
    url = {https://doi.org/10.1016%2Fj.ic.2007.07.001},
    year = {2007},
    month = {nov},
    publisher = {Elsevier {BV}},
    volume = {205},
    number = {11},
    pages = {1652--1670},
    author = {Viliam Geffert},
    title = {Magic numbers in the state hierarchy of finite automata},
    journal = {Information and Computation}
}

@article{Geffert_2007, doi = {10.1016/j.ic.2007.07.001}, url = {https://doi.org/10.1016%2Fj.ic.2007.07.001}, year = {2007}, month = {nov}, publisher = {Elsevier {BV}}, volume = {205}, number = {11}, pages = {1652--1670}, author = {Viliam Geffert}, title = {Magic numbers in the state hierarchy of finite automata}, journal = {Information and Computation} }