Open access
Submitted: 01 December 2010 Published: 15 September 2011
DOI: 10.5772/24022
From the Edited Volume
Edited by Paola Tonino
Submitted: 01 December 2010 Published: 15 September 2011
© 2011 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike-3.0 License, which permits use, distribution and reproduction for non-commercial purposes, provided the original is properly cited and derivative works building on this content are distributed under the same license.