PICHUGOV, S. A. On the existence of a measurable function with given values of the best approximations in $L_0$. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 48, n. 8, p. 1080–1085, 1996. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5251. Acesso em: 27 apr. 2025.