Weighted Approximation by a Class of Bernstein-Type Operators Parvanov, Parvan E. (2011) Mathematica Balkanica New Series AMS classification: 41A36, 41A10, 41A25, 41Al7.
Weighted L 2 inequalities for classical and semiclassical weights. Jung, H.S., Kwon, K.H., Lee, D.W. (1997) Journal of Inequalities and Applications [electronic only]
Weighted uniform approximation on the semiaxis by rational operators. Della Vecchia, B., Mastroianni, G., Szabados, J. (1999) Journal of Inequalities and Applications [electronic only]