NGUYEN, H.-H.; HOANG, N.-T.; NGUYEN, V.-T. On the tangent sets of constraint systems . HPU2 Journal of Science: Natural Sciences and Technology, [S. l.], v. 1, n. 1, p. 31–39, 2022. DOI: 10.56764/hpu2.jos.2022.1.1.31-39. Disponível em: http://sj.hpu2.edu.vn/index.php/journal/article/view/111. Acesso em: 8 jan. 2025.