5. V.F. Babenko, S.V. Borodachov, Optimal approximate integration of r times differentiable functions along a ball using means over spheres (presented at The International Conference “Extremal Problems of Complex and Real Analysis”, Moscow, Russia, May 22—26, 2007 and at The XII International Conference on Approximation Theory, San-Antonio, TX, March 4-8, 2007).
4. V.F. Babenko, S.V. Borodachov, Optimal integration of the class of functions with bounded -norm of the Laplace operator a ball (presented at The Second workshop on Constructive Function Theory, Sam Houston State University, Huntsville, TX, October 26—27, 2007).
3. V.F. Babenko, S.V. Borodachov, On optimization of quadrature formulae on classes of functions with values in Banach spaces (presented at The International Conference “Operator Theory and Stochastic Analysis”, Kiev University, Ukraine, October 2001).
metric.