Melvin Fitting. Possible world semantics for first-order logic of proofs. Annals of Pure and Applied Logic, 165(1):225-240, 2014. [doi]
@article{Fitting14,
title = {Possible world semantics for first-order logic of proofs},
author = {Melvin Fitting},
year = {2014},
doi = {10.1016/j.apal.2013.07.011},
url = {http://dx.doi.org/10.1016/j.apal.2013.07.011},
researchr = {https://researchr.org/publication/Fitting14},
cites = {0},
citedby = {0},
journal = {Annals of Pure and Applied Logic},
volume = {165},
number = {1},
pages = {225-240},
}