P. J. R. Theeven, B. Hemmen, R. P. Geers, R. J. Smeets, P. R. Brink, and H. A. Seelen, “Influence of advanced prosthetic knee joints on perceived performance and everyday life activity level of low-functional persons with a transfemoral amputation or knee disarticulation”, JRM, vol. 44, no. 5, pp. 454–461, Mar. 2012.