Impact of a web based stress management and health promotion program on neck shoulder back pain in knowledge workers : 12 month prospective controlled follow up.
The effectiveness of participatory ergonomics to prevent low-back and neck pain : results of a cluster randomized controlled trial.
Does work stress make you shorter? An ambulatory field study of daily work stressors, job control, and sinal shrinkage.
Epidemiological methods : the effect of envelope type on response rates in epidemiological study of back pain.