1) The Journal of Non-Classical Logic: The Complete Collection 1982-1991
CLE 25 Years Special Edition, 2003
http://www.cle.unicamp.br/jancl/
2) Robert Goldblatt
Topoi, the categorial analysis of logic
Available at "Historical Math Monographs"
Cornell University Library
http://ebooks.library.cornell.edu/cgi/t/text/text-idx?c=math;idno=gold010
3) Stanley N. Burris and H.P. Sankappanavar
A Course in Universal Algebra
** The Millennium Edition **
http://www.math.uwaterloo.ca/~snburris/htdocs/ualg.html
4) Ryszard Wójcicki
Lectures on propositional calculi
Ossolineum, Wroclaw, Poland,1984.
http://www.ifispan.waw.pl/studialogica/wojcicki/papers.html
5) Willem J. Blok and Don Pigozzi
Abstract algebraic logic and the deduction theorem
Preprint, 2001
http://www.math.iastate.edu/dpigozzi/papers/aaldedth.pdf
