@article{Kraj_ek_1997,
    doi = {10.2307/2275541},
    url = {https://doi.org/10.2307%2F2275541},
    year = {1997},
    month = {jun},
    publisher = {Cambridge University Press ({CUP})},
    volume = {62},
    number = {2},
    pages = {457--486},
    author = {Jan Kraj{\'{\i}}{\v{c}}ek},
    title = {Interpolation theorems, lower bounds for proof systems, and independence results for bounded arithmetic},
    journal = {Journal of Symbolic Logic}
}

@article{Kraj_ek_1997, doi = {10.2307/2275541}, url = {https://doi.org/10.2307%2F2275541}, year = {1997}, month = {jun}, publisher = {Cambridge University Press ({CUP})}, volume = {62}, number = {2}, pages = {457--486}, author = {Jan Kraj{\'{\i}}{\v{c}}ek}, title = {Interpolation theorems, lower bounds for proof systems, and independence results for bounded arithmetic}, journal = {Journal of Symbolic Logic} }