Hajnal Andréka, István Németi. Two-variable Logic has Weak, but not Strong, Beth Definability. Journal of Symbolic Logic, 86(2):785-800, 2021. [doi]
@article{AndrekaN21,
title = {Two-variable Logic has Weak, but not Strong, Beth Definability},
author = {Hajnal Andréka and István Németi},
year = {2021},
doi = {10.1017/jsl.2021.7},
url = {https://doi.org/10.1017/jsl.2021.7},
researchr = {https://researchr.org/publication/AndrekaN21},
cites = {0},
citedby = {0},
journal = {Journal of Symbolic Logic},
volume = {86},
number = {2},
pages = {785-800},
}