Change Log

Major update published on 21 March 2013

One of the key features of Living Reviews is that its articles are kept up-to-date by their authors. A major update is considered a new publication. As such it is again subject to peer review and is issued with a new publication number.

Global description:

The review has been thoroughly revised and updated. Added Sections 3.8 and 5.1 and 8 new figures (3 were removed). 55 new references have been included (4 were removed).

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