Charles E. Hughes. Triadic partial implicational propositional calculi. Math. Log. Q., 21(1):21-28, 1975. [doi]
@article{Hughes75-0,
title = {Triadic partial implicational propositional calculi},
author = {Charles E. Hughes},
year = {1975},
doi = {10.1002/malq.19750210103},
url = {http://dx.doi.org/10.1002/malq.19750210103},
researchr = {https://researchr.org/publication/Hughes75-0},
cites = {0},
citedby = {0},
journal = {Math. Log. Q.},
volume = {21},
number = {1},
pages = {21-28},
}