1. Sul’din P: Wiener measure and its applications to approximation theory I. Izv. Vysš. Učebn. Zaved., Mat. 1959, 6: 145–158. (in Russian)
2. Sul’din P: Wiener measure and its applications to approximation theory II. Izv. Vysš. Učebn. Zaved., Mat. 1960, 5: 165–179. (in Russian)
3. Traub JF, Wasilkowski GW, Woźniakowski H: Information-Based Complexity. Academic Press, New York; 1988.
4. Maiorov VE: Discretization of the problem of diameters. Usp. Mat. Nauk 1975, 30: 179–180.
5. Maiorov VE: On linear widths of Sobolev classes and chains of extremal subspaces. Mat. Sb. 1980, 113(115):437–463. English transl. in Math. USSR Sb. 41 (1982)