Grundt Larsen, I. et al. 2019. Effect of adding lay-tutors to the educational part of a back school programme for patients with subacute, non-specific low back pain: A randomized controlled clinical trial with a two-year follow-up. Journal of Rehabilitation Medicine. 51, 9 (Sep. 2019), 698–704. DOI:https://doi.org/10.2340/16501977-2584.