1. S. N. Bernstein, “On the best approximation of continuous functions on the entire real axis with the use of entire functions of given power,” in: S. N. Bernstein, Collected Works [in Russian], Vol. 2, Academy of Sciences of the USSR, Moscow (1952), pp. 371–375.
2. N. I. Akhiezer, Lectures on Approximation Theory [in Russian], Nauka, Moscow (1947).
3. A. F. Timan, Approximation Theory of Functions of a Real Variable [in Russian], Fizmatgiz, Moscow (1960).
4. A. F. Timan, “Approximation of functions defined on the entire real axis by entire functions of exponential type,” Izv. Vyssh. Uchebn. Zaved., Ser. Mat., No. 2, 89–101 (1968).
5. S. M. Nikol’skii, Approximation of Functions of Many Variables and Imbedding Theorems [in Russian], Nauka, Moscow (1969).