Theeven, P. J. R., B. Hemmen, F. Rings, G. H. Meys, P. R. Brink, R. J. Smeets, and H. A. Seelen. “Functional Added Value of Microprocessor-Controlled Knee Joints in Daily Life Performance of Medicare Functional Classification Level-2 Amputees”. Journal of Rehabilitation Medicine, vol. 43, no. 10, Aug. 2011, pp. 906-15, doi:10.2340/16501977-0861.