Melvin Fitting. A tableau system for propositional S5. Notre Dame Journal of Formal Logic, 18(2):292-294, 1977. [doi]
@article{Fitting77,
title = {A tableau system for propositional S5},
author = {Melvin Fitting},
year = {1977},
doi = {10.1305/ndjfl/1093887933},
url = {http://dx.doi.org/10.1305/ndjfl/1093887933},
researchr = {https://researchr.org/publication/Fitting77},
cites = {0},
citedby = {0},
journal = {Notre Dame Journal of Formal Logic},
volume = {18},
number = {2},
pages = {292-294},
}