Toida, Shunichi (2 August 2009). "Proof of Implications". CS381 Discrete Structures/Discrete Mathematics Web Course Material. Department of Computer Science, Old Dominion University. Retrieved 10 March 2010.
Lucas, Peter; Gaag, Linda van der (1991). Principles of expert systems(PDF). International computer science series. Wokingham, England; Reading, Mass: Addison-Wesley. p. 26. ISBN978-0-201-41640-4.
Franks, Curtis (2023), "Propositional Logic", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Fall 2023 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
McGrath, Matthew; Frank, Devin (2023), "Propositions", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Winter 2023 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
Bobzien, Susanne (1 January 2016). "Ancient Logic". In Zalta, Edward N. (ed.). The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University – via Stanford Encyclopedia of Philosophy.
Bobzien, Susanne (2020), "Ancient Logic", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Summer 2020 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
Peckhaus, Volker (1 January 2014). "Leibniz's Influence on 19th Century Logic". In Zalta, Edward N. (ed.). The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University – via Stanford Encyclopedia of Philosophy.
Dutilh Novaes, Catarina (2022), "Argument and Argumentation", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Fall 2022 ed.), Metaphysics Research Lab, Stanford University, retrieved 5 April 2024
Pelletier, Francis Jeffry; Hazen, Allen (2024), "Natural Deduction Systems in Logic", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Spring 2024 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
Restall, Greg (2018), "Substructural Logics", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Spring 2018 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
Paseau, Alexander; Pregel, Fabian (2023), "Deductivism in the Philosophy of Mathematics", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Fall 2023 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
Demey, Lorenz; Kooi, Barteld; Sack, Joshua (2023), "Logic and Probability", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Fall 2023 ed.), Metaphysics Research Lab, Stanford University, retrieved 22 March 2024
Shramko, Yaroslav; Wansing, Heinrich (2021), "Truth Values", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Winter 2021 ed.), Metaphysics Research Lab, Stanford University, retrieved 23 March 2024
Shapiro, Stewart; Kouri Kissel, Teresa (2024), "Classical Logic", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Spring 2024 ed.), Metaphysics Research Lab, Stanford University, retrieved 25 March 2024
Aloni, Maria (2023), "Disjunction", in Zalta, Edward N.; Nodelman, Uri (eds.), The Stanford Encyclopedia of Philosophy (Spring 2023 ed.), Metaphysics Research Lab, Stanford University, retrieved 23 March 2024