1. Unification theory;Baader,1993
2. Logics containing K4, Part I;Fine;J. Symbolic Logic,1974
3. Logics containing K4, Part II;Fine;J. Symbolic Logic,1985
4. Unification through projectivity;Ghilardi;J. Logic Comput.,1997
5. Unification in intuitionistic logic;Ghilardi;J. Symbolic Logic,1999