@article{PFENNING_2001,
    doi = {10.1017/s0960129501003322},
    url = {https://doi.org/10.1017%2Fs0960129501003322},
    year = {2001},
    month = {jul},
    publisher = {Cambridge University Press ({CUP})},
    volume = {11},
    number = {04},
    author = {FRANK PFENNING and ROWAN DAVIES},
    title = {A judgmental reconstruction of modal logic},
    journal = {Mathematical Structures in Computer Science}
}

@article{PFENNING_2001, doi = {10.1017/s0960129501003322}, url = {https://doi.org/10.1017%2Fs0960129501003322}, year = {2001}, month = {jul}, publisher = {Cambridge University Press ({CUP})}, volume = {11}, number = {04}, author = {FRANK PFENNING and ROWAN DAVIES}, title = {A judgmental reconstruction of modal logic}, journal = {Mathematical Structures in Computer Science} }