@article{Kapovich_2002,
    doi = {10.1006/jabr.2001.9033},
    url = {https://doi.org/10.1006%2Fjabr.2001.9033},
    year = {2002},
    month = {feb},
    publisher = {Elsevier {BV}},
    volume = {248},
    number = {2},
    pages = {608--668},
    author = {Ilya Kapovich and Alexei Myasnikov},
    title = {Stallings Foldings and Subgroups of Free Groups},
    journal = {Journal of Algebra}
}

@article{Kapovich_2002, doi = {10.1006/jabr.2001.9033}, url = {https://doi.org/10.1006%2Fjabr.2001.9033}, year = {2002}, month = {feb}, publisher = {Elsevier {BV}}, volume = {248}, number = {2}, pages = {608--668}, author = {Ilya Kapovich and Alexei Myasnikov}, title = {Stallings Foldings and Subgroups of Free Groups}, journal = {Journal of Algebra} }