An explicit basis for the admissible inference rules in the Gödel-Löb logic GL. Fedorishin, B.R. — 2007 Sibirskij Matematicheskij Zhurnal
An inheritance criterion for the admissible inference rules of K4. Rutskij, A.N.; Fedorishin, B.R. — 2002 Sibirskij Matematicheskij Zhurnal