1.
ERTOLA BIRABEN, Rodolfo. J. Michael Dunn and Gary M. Hardegree, "Algebraic Methods in Philosophical Logic", Oxford Logic Guides, no. 41. Logic and Logical Philosophy. Online. 23 December 2005. Vol. 14, no. 2, pp. 265-267. [Accessed 14 June 2026]. DOI 10.12775/LLP.2005.017.