Cost effectiveness of physiotherapy, manual therapy, and general practitioner care for neck pain: economic evaluation alongside a randomised controlled trial. - Korthals de Bos,I.B.; Hoving,J.L.; Tulder,M.W van.; Rutten van Molken,M.P.; Ader,H.J.; de Vet,H.C.; Koes,B.W.; Vondeling,H.; Bouter,L.M. (BMJ, 2003)