TITLE: Good textbook for learning Sequent Calculus
QUESTION [8 upvotes]: There are many modern text books teaching logic using Natural Deduction.
There are no books teaching logic using the axiomatic method (see Good book for learning and practising axiomatic logic )
Now in another post (Prove by introduction rules (P ⇒ Q) || (Q ⇒ R)⇒ (P NOT Q ⇒ R), (P ⇒ Q)⇒ !Q⇒ !P + more. ) somebody is struggling with sequent calculus
( http://en.wikipedia.org/wiki/Sequent_calculus ) 
Are there good textbooks to study logic using the sequent calculus method (or do you just have to be fluent in natural deduction before you should even have a look at it)?

REPLY [3 votes]: I learned sequent calculus from the first couple of chapters of Takeuti's text (Proof Theory, now out of print: http://www.amazon.com/Proof-Theory-Studies-Foundations-Mathematics/dp/0444879439).  
I can't really compare it with other texts, but I found it worked well for me.