Mario Coppo, Mariangiola Dezani-Ciancaglini, Betti Venneri. Functional Characters of Solvable Terms. Math. Log. Q., 27(2-6):45-58, 1981. [doi]
@article{CoppoDV81,
title = {Functional Characters of Solvable Terms},
author = {Mario Coppo and Mariangiola Dezani-Ciancaglini and Betti Venneri},
year = {1981},
doi = {10.1002/malq.19810270205},
url = {http://dx.doi.org/10.1002/malq.19810270205},
researchr = {https://researchr.org/publication/CoppoDV81},
cites = {0},
citedby = {0},
journal = {Math. Log. Q.},
volume = {27},
number = {2-6},
pages = {45-58},
}