Bansevičius, R., and J. A. Virbalis. “Relief Formation on the Plane: Principal Solutions, Investigation and Application for the Blind”. Elektronika ir Elektrotechnika 64, no. 8 (October 20, 2005): 46-46. Accessed September 29, 2022. https://eejournal.ktu.lt/index.php/elt/article/view/10539.