GREGORY, JOHN; PERICAK-SPECTOR, KATHLEEN. New methods of solving general constrained calculus of variations problems involving pdes. Utilitas Mathematica , [S. l.], v. 58, 2000. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/179. Acesso em: 3 feb. 2026.