@article{Lohrey_2008,
    doi = {10.1016/j.jalgebra.2007.08.025},
    url = {https://doi.org/10.1016%2Fj.jalgebra.2007.08.025},
    year = {2008},
    month = {jul},
    publisher = {Elsevier {BV}},
    volume = {320},
    number = {2},
    pages = {728--755},
    author = {Markus Lohrey and Benjamin Steinberg},
    title = {The submonoid and rational subset membership problems for graph groups},
    journal = {Journal of Algebra}
}

@article{Lohrey_2008, doi = {10.1016/j.jalgebra.2007.08.025}, url = {https://doi.org/10.1016%2Fj.jalgebra.2007.08.025}, year = {2008}, month = {jul}, publisher = {Elsevier {BV}}, volume = {320}, number = {2}, pages = {728--755}, author = {Markus Lohrey and Benjamin Steinberg}, title = {The submonoid and rational subset membership problems for graph groups}, journal = {Journal of Algebra} }