@article{Coppo_1980,
    doi = {10.1305/ndjfl/1093883253},
    url = {https://doi.org/10.1305%2Fndjfl%2F1093883253},
    year = {1980},
    month = {oct},
    publisher = {Duke University Press},
    volume = {21},
    number = {4},
    author = {M. Coppo and M. Dezani-Ciancaglini},
    title = {An extension of the basic functionality theory for the {\textdollar}{\textbackslash}lambda{\textdollar}-calculus.},
    journal = {Notre Dame Journal of Formal Logic}
}

@article{Coppo_1980, doi = {10.1305/ndjfl/1093883253}, url = {https://doi.org/10.1305%2Fndjfl%2F1093883253}, year = {1980}, month = {oct}, publisher = {Duke University Press}, volume = {21}, number = {4}, author = {M. Coppo and M. Dezani-Ciancaglini}, title = {An extension of the basic functionality theory for the {\textdollar}{\textbackslash}lambda{\textdollar}-calculus.}, journal = {Notre Dame Journal of Formal Logic} }