- L. Baratchart, F.L. Nazarov, V.V. Peller, “Analytic approximation of matrix functions in Lp”, Journal of Approximation Theory, 158, no. 2, 2009, 242
- Alberto A. Condori, “On the sum of superoptimal singular values”, Journal of Functional Analysis, 257, no. 3, 2009, 659