YAKAR, A.; KUTLAY, H. Extensions of some differential inequalities for fractional integro-differential equations via upper and lower solutions. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 109, n. 1, p. 156–167, 2023. DOI: 10.31489/2023m1/156-167. Disponível em: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/560. Acesso em: 10 jul. 2025.