@article{Engelfriet_2021,
    doi = {10.1016/j.tcs.2020.10.030},
    url = {https://doi.org/10.1016%2Fj.tcs.2020.10.030},
    year = {2021},
    month = {jan},
    publisher = {Elsevier {BV}},
    volume = {850},
    pages = {40--97},
    author = {Joost Engelfriet and Hendrik Jan Hoogeboom and Bart Samwel},
    title = {{XML} navigation and transformation by tree-walking automata and transducers with visible and invisible pebbles},
    journal = {Theoretical Computer Science}
}

@article{Engelfriet_2021, doi = {10.1016/j.tcs.2020.10.030}, url = {https://doi.org/10.1016%2Fj.tcs.2020.10.030}, year = {2021}, month = {jan}, publisher = {Elsevier {BV}}, volume = {850}, pages = {40--97}, author = {Joost Engelfriet and Hendrik Jan Hoogeboom and Bart Samwel}, title = {{XML} navigation and transformation by tree-walking automata and transducers with visible and invisible pebbles}, journal = {Theoretical Computer Science} }