1. Abe, J.M.: Fundamentos da lógica anotada, (Foundations of annotated logics), in Portuguese, Ph.D. thesis, University of São Paulo, São Paulo, p. 135 (1992)
2. Abe, J.M.: Some Aspects of Paraconsistent Systems and Applications. Logique et Analyse 15, 83–96 (1997)
3. Cresswell, M.J.: Intensional logics and logical truth. Journal of Philosophical Logic 1, 2–15 (1972)
4. Cresswell, M.J.: Logics and Languages. Methuen and Co., London (1973)
5. Da Costa, N.C.A.: On the theory of inconsistent formal systems. Notre Dame J. of Formal Logic 15, 497–510 (1974)