Nuel Belnap, Storrs McCall. Every functionally complete m-valued logic has a Post-complete axiomatization. Notre Dame Journal of Formal Logic, 11(1):106, 1970. [doi]
@article{BelnapM70,
title = {Every functionally complete m-valued logic has a Post-complete axiomatization},
author = {Nuel Belnap and Storrs McCall},
year = {1970},
doi = {10.1305/ndjfl/1093893866},
url = {http://dx.doi.org/10.1305/ndjfl/1093893866},
researchr = {https://researchr.org/publication/BelnapM70},
cites = {0},
citedby = {0},
journal = {Notre Dame Journal of Formal Logic},
volume = {11},
number = {1},
pages = {106},
}