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I was wondering if there is much of a difference between the 2012 and 2013 editions of Lathrope's Selected Federal Taxation Statutes and Regulations? Its required for my fundamental income tax class.

Can you get away with using Westlaw, Lexis, or the government website itself and save $. I know I can in my tax class.

Best one to use is http://www.law.cornell.edu/uscode/text/26/1
(trick is to just change the code section in the URL to switch between.
Real trick is to download the chapter you need, and use that the entire semester and also on the exam. You toggle through the contents in the pane on the left)

Second best one to use is http://www.fourmilab.ch/ustax/www/sections.html