@article{BSL_2018_47_4_a2,
     author = {{\L}yczak, Marcin and Pietruszczak, Andrzej},
     title = {On the {Definability} of {Le\'sniewski{\textquoteright}s} {Copula} {\textquoteleft}is{\textquoteright} in {Some} {Ontology-Like} {Theories}},
     journal = {Bulletin of the Section of Logic},
     publisher = {mathdoc},
     volume = {47},
     number = {4},
     year = {2018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BSL_2018_47_4_a2/}
}