Kaupp, Gerd. “The Loading Curve of Spherical Indentions Is Not a Parabola and Flat Punch Is Linear: Scientific Explanation”. Basic Mathematics for Physically Correct Mechanical Properties from Indentations (October 28, 2022): 125–145. Accessed June 12, 2026. https://stm.bookpi.org/BMPCMPI/article/view/8534.