Approximation theory.

1. J. Bustamante, C. Castaneda, “Direct and inverse results in Hölder norms”, Journal of Approximation Theory, 138 (2006), 112–123      
2. J. Bustamante, “Estimates of positive linear operators in terms of second-order moduli”, J. Math. Anal. Appl., 345 (2008), 203–212    
3. J. Bustamante, J. M. Quesada, “On an extremal relation of Bernstein operators”, Journal of Approximation Theory, 141 (2006), 214–215      

• Benemérita Universidad Autónoma de Puebla