Gruther, W., T. Benesch, C. Zorn, T. Paternostro-Sluga, M. Quittan, V. Fialka-Moser, C. Spiss, F. Kainberger, and R. Crevenna. “ Quadriceps Femoris Muscle Layer”. Journal of Rehabilitation Medicine, vol. 40, no. 3, Mar. 2008, pp. 185-9, doi:10.2340/16501977-0139.