Introductions to classical and nonclassical logic? I've found Eric Schechter: Classical and Nonclassical Logics: An Introduction to the Mathematics of Propositions a really nice book. But I'd like to skim through other books about the same subject, at the moment, I've been able to find only these ones:


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*An Introduction to Non-Classical Logic: From If to Is.

*Logical Options: An Introduction to Classical and Alternative Logics.
Can you suggest me more introductory books to classical and nonclassical logics?

Merrie Bergmann's An Introduction to Many-Valued and Fuzzy Logic covers first-order classical, three-valued, and fuzzy logic (including sections on quantification theory in classical, three-valued, and fuzzy logic).
A classic textbook on many-valued logic is Rosser and Turquette's Many-valued Logics.
Gottwald has A Treatise on Many-Valued Logics.
Richard L. Epstein's book Propositional Logicsseems similar to Schecter's in that many different kinds of propositional logics get covered.
You might also want to look at papers... in the volume Polish Logic I know there's a few papers by Wajsberg one on three-valued logic, and another which all sorts of different axiom sets for the implicational calculus of propositions.
I also highly recommend A. N. Prior's Formal Logic (2nd edition) which has a highly useful and still rather comprehensive appendix of different axiom sets for logical calculi.
The 2nd appendix in the 2nd edition also contains a proof that tells you about lots of classical implicational calculi.
Additionally, you might want to see Ted Ulrich's pages which cover different axiom sets (almost entirely single axioms, but multiple axiom sets also get discussed) for a few logical calculi. 
