@article{Leivant_1993,
    doi = {10.1016/0304-3975(93)90092-8},
    url = {https://doi.org/10.1016%2F0304-3975%2893%2990092-8},
    year = {1993},
    month = {dec},
    publisher = {Elsevier {BV}},
    volume = {121},
    number = {1-2},
    pages = {309--321},
    author = {Daniel Leivant},
    title = {Functions over free algebras definable in the simply typed lambda calculus},
    journal = {Theoretical Computer Science}
}

@article{Leivant_1993, doi = {10.1016/0304-3975(93)90092-8}, url = {https://doi.org/10.1016%2F0304-3975%2893%2990092-8}, year = {1993}, month = {dec}, publisher = {Elsevier {BV}}, volume = {121}, number = {1-2}, pages = {309--321}, author = {Daniel Leivant}, title = {Functions over free algebras definable in the simply typed lambda calculus}, journal = {Theoretical Computer Science} }