TY - BOOK AU - Gradshtein, I. S. AU - Boddington, T. TI - DIRECTAND CONVERSE THEOREMS U1 - 512.817 PY - 1963/// CY - London PB - Pergamon Press KW - Aggregates KW - Axioms KW - Logic. Symbolic And Mathematical N1 - A Translation Of : Pryamayai Obratnaya Teoremy -- Elementry Algebry Logiki ER -