Necessary Conditions for the Existence of a Saddle Point in one Optimal Control Problem for Systems of Hyperbolic Equations. European Journal of Pure and Applied Mathematics, Maryland, USA, v. 14, n. 4, p. 1402–1414, 2021. DOI: 10.29020/nybg.ejpam.v14i4.4135. Disponível em: https://ejpam.com/index.php/ejpam/article/view/4135.. Acesso em: 3 jul. 2024.