@article{Yen_1992,
    doi = {10.1016/0890-5401(92)90059-o},
    url = {https://doi.org/10.1016%2F0890-5401%2892%2990059-o},
    year = {1992},
    month = {jan},
    publisher = {Elsevier {BV}},
    volume = {96},
    number = {1},
    pages = {119--137},
    author = {Hsu-Chun Yen},
    title = {A unified approach for deciding the existence of certain petri net paths},
    journal = {Information and Computation}
}

@article{Yen_1992, doi = {10.1016/0890-5401(92)90059-o}, url = {https://doi.org/10.1016%2F0890-5401%2892%2990059-o}, year = {1992}, month = {jan}, publisher = {Elsevier {BV}}, volume = {96}, number = {1}, pages = {119--137}, author = {Hsu-Chun Yen}, title = {A unified approach for deciding the existence of certain petri net paths}, journal = {Information and Computation} }