VALIUKEVIČIUS, G. Notion of the virtual derivative. Nonlinear Analysis: Modelling and Control, [S. l.], v. 16, n. 1, p. 116–122, 2011. DOI: 10.15388/NA.16.1.14119. Disponível em: https://www.zurnalai.vu.lt/nonlinear-analysis/article/view/14119. Acesso em: 3 may. 2025.