@article{Droms_1987,
    doi = {10.1016/0021-8693(87)90010-x},
    url = {https://doi.org/10.1016%2F0021-8693%2887%2990010-x},
    year = {1987},
    month = {apr},
    publisher = {Elsevier {BV}},
    volume = {106},
    number = {2},
    pages = {484--489},
    author = {Carl Droms},
    title = {Graph groups, coherence, and three-manifolds},
    journal = {Journal of Algebra}
}

@article{Droms_1987, doi = {10.1016/0021-8693(87)90010-x}, url = {https://doi.org/10.1016%2F0021-8693%2887%2990010-x}, year = {1987}, month = {apr}, publisher = {Elsevier {BV}}, volume = {106}, number = {2}, pages = {484--489}, author = {Carl Droms}, title = {Graph groups, coherence, and three-manifolds}, journal = {Journal of Algebra} }