Mariana Ivanova Boteva, Ivan Mihaylov Mihaylov, and Ivan Nikolov Shopov. “RESEARCH OF THE EFFECT OF THE VELOCITY COEFICIENT ON THE CUTTING FORCE OF VEGETABLES”. World Science, Vol. 1, no. 2(6), Feb. 2016, pp. 6-9, https://rsglobal.pl/index.php/ws/article/view/834.