1. Criteria for the existence of derivatives in Lp;Brudnyi;Math. USSR-Sb.,1967
2. The degree of best approximation in the Lipschitz norm by trigonometric polynomials;Bustamante;Aportaciones Mat. Comun.,1999
3. J. Bustamante, M.A. Jiménez, Trends in Hölder approximation, in: Proceedings of the Fifth International Conference on Approximation and Optimization in the Caribbean, Guadeloupe, France, 1999.
4. Approximation, Optimization and Mathematical Economics,2001
5. Direct and inverse results in Hölder norms;Bustamante;J. Approx. Theory,2006