@article{Coppo_1981,
    doi = {10.1002/malq.19810270205},
    url = {https://doi.org/10.1002%2Fmalq.19810270205},
    year = {1981},
    month = {jan},
    publisher = {Wiley},
    volume = {27},
    number = {2-6},
    pages = {45--58},
    author = {M. Coppo and M. Dezani-Ciancaglini and B. Venneri},
    title = {Functional Characters of Solvable Terms},
    journal = {Mathematical Logic Quarterly}
}

@article{Coppo_1981, doi = {10.1002/malq.19810270205}, url = {https://doi.org/10.1002%2Fmalq.19810270205}, year = {1981}, month = {jan}, publisher = {Wiley}, volume = {27}, number = {2-6}, pages = {45--58}, author = {M. Coppo and M. Dezani-Ciancaglini and B. Venneri}, title = {Functional Characters of Solvable Terms}, journal = {Mathematical Logic Quarterly} }