@article{Perst_2004,
    doi = {10.1016/j.ipl.2003.05.001},
    url = {https://doi.org/10.1016%2Fj.ipl.2003.05.001},
    year = {2004},
    month = {feb},
    publisher = {Elsevier {BV}},
    volume = {89},
    number = {3},
    pages = {141--149},
    author = {Thomas Perst and Helmut Seidl},
    title = {Macro forest transducers},
    journal = {Information Processing Letters}
}

@article{Perst_2004, doi = {10.1016/j.ipl.2003.05.001}, url = {https://doi.org/10.1016%2Fj.ipl.2003.05.001}, year = {2004}, month = {feb}, publisher = {Elsevier {BV}}, volume = {89}, number = {3}, pages = {141--149}, author = {Thomas Perst and Helmut Seidl}, title = {Macro forest transducers}, journal = {Information Processing Letters} }