@article{Cichon_1998,
    doi = {10.1016/s0304-3975(97)00009-1},
    url = {https://doi.org/10.1016%2Fs0304-3975%2897%2900009-1},
    year = {1998},
    month = {jul},
    publisher = {Elsevier {BV}},
    volume = {201},
    number = {1-2},
    pages = {63--84},
    author = {E.A. Cichon and E.Tahhan Bittar},
    title = {Ordinal recursive bounds for Higman{\textquotesingle}s theorem},
    journal = {Theoretical Computer Science}
}

@article{Cichon_1998, doi = {10.1016/s0304-3975(97)00009-1}, url = {https://doi.org/10.1016%2Fs0304-3975%2897%2900009-1}, year = {1998}, month = {jul}, publisher = {Elsevier {BV}}, volume = {201}, number = {1-2}, pages = {63--84}, author = {E.A. Cichon and E.Tahhan Bittar}, title = {Ordinal recursive bounds for Higman{\textquotesingle}s theorem}, journal = {Theoretical Computer Science} }