1. Eliminating unorthodox derivation rules in an axiom system for iteration-free PDL with intersection;Balbiani;Fundam. Inform.,2003
2. Complete axiomatization of a relative modal logic with composition and intersection;Balbiani;J. of Applied Non-Classical Logics,1998
3. Iteration-free PDL with Intersection: a Complete Axiomatization;Balbiani;Fundam. Inform.,2001
4. PDL with Intersection of Programs: A Complete Axiomatization;Balbiani;J. of Applied Non-Classical Logics,2003
5. Propositional dynamic logic is weaker without tests;Berman;TCS,1981