On the Existence of Non-Negative Solution to the Cauchy Problem in Dynamic Economic Models. Advances in Systems Science and Applications, [S. l.], v. 26, n. 1, p. 148–153, 2026. DOI: 10.25728/assa.2026.26.1.2205. Disponível em: https://ijassa.ipu.ru/index.php/ijassa/article/view/2205. Acesso em: 11 sep. 2026.