@article{Finkel_2009,
    doi = {10.3233/fi-2009-151},
    url = {https://doi.org/10.3233%2Ffi-2009-151},
    year = {2009},
    publisher = {{IOS} Press},
    volume = {95},
    number = {2-3},
    pages = {287--303},
    author = {Olivier Finkel and Pierre Simonnet},
    title = {On Recognizable Tree Languages Beyond the Borel Hierarchy},
    journal = {Fundamenta Informaticae}
}

@article{Finkel_2009, doi = {10.3233/fi-2009-151}, url = {https://doi.org/10.3233%2Ffi-2009-151}, year = {2009}, publisher = {{IOS} Press}, volume = {95}, number = {2-3}, pages = {287--303}, author = {Olivier Finkel and Pierre Simonnet}, title = {On Recognizable Tree Languages Beyond the Borel Hierarchy}, journal = {Fundamenta Informaticae} }