SÁNDOR, Kajántó. Riccati Pairs ̶ New Approach for Hardy–Rellich Inequalities. [s.l.] : Presa Universitară Clujeană,2025. Disponível em: https://editura.ubbcluj.ro/index.php/puc/catalog/book/3956. Acesso em: 19 mar. 2026.