Swanenburg, J., P. Koch, N. Meier, and B. Wirth. “Function and Activity in Patients With Knee Arthroplasty: Validity and Reliability of a German Version of the Lysholm Score and the Tegner Activity Scale”. Swiss Medical Weekly, vol. 144, no. 2324, June 2014, p. w13976, doi:10.4414/smw.2014.13976.