@article{Fischer_1979,
    doi = {10.1016/0022-0000(79)90046-1},
    url = {https://doi.org/10.1016%2F0022-0000%2879%2990046-1},
    year = {1979},
    month = {apr},
    publisher = {Elsevier {BV}},
    volume = {18},
    number = {2},
    pages = {194--211},
    author = {Michael J. Fischer and Richard E. Ladner},
    title = {Propositional dynamic logic of regular programs},
    journal = {Journal of Computer and System Sciences}
}

@article{Fischer_1979, doi = {10.1016/0022-0000(79)90046-1}, url = {https://doi.org/10.1016%2F0022-0000%2879%2990046-1}, year = {1979}, month = {apr}, publisher = {Elsevier {BV}}, volume = {18}, number = {2}, pages = {194--211}, author = {Michael J. Fischer and Richard E. Ladner}, title = {Propositional dynamic logic of regular programs}, journal = {Journal of Computer and System Sciences} }