Polijaniuk, A., and Z. Handzel-Powierża. “Influence of Microgeometry of Surcafes on the Contact Approach of Elements With a Surface Layer”.
Engineering Transactions, vol. 41, no. 1, Mar. 1993, pp. 51-60,
https://et.ippt.pan.pl/index.php/et/article/view/1554.