Chapter 4. European guidelines for the management of chronic nonspecific low back pain - Airaksinen,O.; Brox,JI.; Cedraschi,C.; Hildebrandt,J.; Klaber-Moffett,J.; Kovacs,F.; Mannion,AF.; Reis,S.; Staal,JB.; Ursin,H.; Zanoli,G. (Eur Spine J, 2006)