1. S. Artemov, Operational modal logic, Technical Report MSI 95-29, Cornell University, December, 1995
2. Explicit provability and constructive semantics;Artemov;The Bulletin for Symbolic Logic,2001
3. V. Brezhnev, On explicit counterparts of modal logics, Technical Report CFIS 2000-06, Cornell University, 2000
4. On the logic of proofs;Brezhnev,2001