@article{Kozen_1995,
    doi = {10.1017/s0960129500000657},
    url = {https://doi.org/10.1017%2Fs0960129500000657},
    year = {1995},
    month = {mar},
    publisher = {Cambridge University Press ({CUP})},
    volume = {5},
    number = {1},
    pages = {113--125},
    author = {Dexter Kozen and Jens Palsberg and Michael I. Schwartzbach},
    title = {Efficient recursive subtyping},
    journal = {Mathematical Structures in Computer Science}
}

@article{Kozen_1995, doi = {10.1017/s0960129500000657}, url = {https://doi.org/10.1017%2Fs0960129500000657}, year = {1995}, month = {mar}, publisher = {Cambridge University Press ({CUP})}, volume = {5}, number = {1}, pages = {113--125}, author = {Dexter Kozen and Jens Palsberg and Michael I. Schwartzbach}, title = {Efficient recursive subtyping}, journal = {Mathematical Structures in Computer Science} }