1. Anderson, A. R., & Belnap, N. D. (1975). Entailment: The logic of relevance and necessity (Vol. 1). Princeton: Princeton University Press.
2. Anderson, A. R., Belnap, N. D., & Dunn, J. M. (1992). Entailment: The logic of relevance and necessity (Vol. 2). Princeton: Princeton University Press.
3. Bezhanishvili, G., Moraschini, T., & Raftery, J. G. (2017). Epimorphisms in varieties of residuated structures. Journal of Algebra, 492, 185–211.
4. Blok, W. J., & Hoogland, E. (2006). The Beth property in algebraic logic. Studia Logica, 83, 49–90.
5. Brady, R. (Ed.). (2003). Relevant logics and their rivals (Vol. 2). Farnham: Ashgate.