@incollection{Buss_1995,
    doi = {10.1016/s0049-237x(06)80038-8},
    url = {https://doi.org/10.1016%2Fs0049-237x%2806%2980038-8},
    year = {1995},
    publisher = {Elsevier},
    pages = {29--68},
    author = {Samuel R. Buss},
    title = {The witness function method and provably recursive functions of peano arithmetic},
    booktitle = {Logic, Methodology and Philosophy of Science {IX}, Proceedings of the Ninth International Congress of Logic, Methodology and Philosophy of Science}
}

@incollection{Buss_1995, doi = {10.1016/s0049-237x(06)80038-8}, url = {https://doi.org/10.1016%2Fs0049-237x%2806%2980038-8}, year = {1995}, publisher = {Elsevier}, pages = {29--68}, author = {Samuel R. Buss}, title = {The witness function method and provably recursive functions of peano arithmetic}, booktitle = {Logic, Methodology and Philosophy of Science {IX}, Proceedings of the Ninth International Congress of Logic, Methodology and Philosophy of Science} }