1. Is strict implication the same as entailment?;Duncan-Jones;Analysis,1934
2. Anderson Alan Ross , Completeness theorems for the systems E of entailment and EQ of entailment with quantification, forthcoming.
3. Begründung einer strengen Implikation;Ackermann;this Journal,1956
4. III.—INTENSIONAL RELATIONS
5. Implication and Subsumption