Columbia subject headings:
Leśniewski, Stanisław, 1886-1939.
Logic, Symbolic and mathematical.
Ontology.
Semantics (Philosophy)
Harvard subject headings:
Leśniewski, Stanisław, 1886-1939.
Logic, Symbolic and mathematical.
Ontology.
Semantics (Philosophy)
Princeton subject headings:
Leśniewski, Stanisław, 1886-1939.
Metamathematics.
Model theory.