Verdoodt, Ann. «Orthonormal bases for spaces of continous and continuously differentiable functions defined on a subset». Revista Matemática Complutense 9, no. 2 (enero 1, 1996): 295. Accedido julio 30, 2026. https://revistas.ucm.es/index.php/REMA/article/view/REMA9696230295A.