1. Medium-firm mattresses reduced pain-related disability more than firm mattress in chronic, nonspecific low-back pain;Hadler;ACP Journal Club,2004
2. Individually prescribed sleep surfaces based on sleeping positions improve back pain and sleep quality;Jacobson;Journal of Applied Ergonomics,2010
3. Back pain, sleep quality and perceived. Stress following introduction of new of bedding systems;Jacobson;Journal of Chiropractic Medicine,2009
4. Effect of firmness of mattress on chronic non-specific low-back pain: Randomized, double-blind, controlled, multicentre trial;Kovacs;Lancet,2003
5. Physiologic responses during rest on a sleep system at varied degrees of firmness in a normal population;Lahm;Ergonomics,2002