− | * [[Kevin C. Klement|Klement, Kevin C.]] (2006), "Propositional Logic", in James Fieser and Bradley Dowden (eds.), ''[[Internet Encyclopedia of Philosophy]]'', [http://www.iep.utm.edu/p/prop-log.htm Eprint]. | + | * Klement, Kevin C. (2006), "Propositional Logic", in James Fieser and Bradley Dowden (eds.), ''Internet Encyclopedia of Philosophy''. [http://www.iep.utm.edu/p/prop-log.htm Online]. |
− | * [http://www.ltn.lv/~podnieks/mlog/ml2.htm Introduction to Mathematical Logic] | + | * Magnus, P.D. ''[http://www.fecundity.com/logic/ Forall x : An Introduction to Formal Logic]''. |
− | * [http://www.visualstatistics.net/Scaling/Propositional%20Calculus/Elements%20of%20Propositional%20Calculus.htm Elements of Propositional Calculus] | + | * [http://www.visualstatistics.net/Scaling/Propositional%20Calculus/Elements%20of%20Propositional%20Calculus.htm Elements of Propositional Calculus]. |
− | * ''[http://www.fecundity.com/logic/ forall x: an introduction to formal logic]'', by P.D. Magnus, covers formal semantics and proof theory for sentential logic. | + | * [http://www.ltn.lv/~podnieks/mlog/ml2.htm Introduction to Mathematical Logic]. |