1. S. N. Bernshtein, “On the best approximation of continuous functions on the whole real axis by entire functions of a given power,” in: Collection of Works of S.N. Bernshtein [in Russian], AS SSSR, Moscow, 1952, Vol. 2, pp. 371–375.
2. N. I. Achiezer, Theory of Approximation, Ungar, New York, 1956.
3. A. F. Timan, Theory of Approximation of Functions of a Real Variable, Dover, New York, 1964.
4. M. F. Timan, “The approximation of functions given on the whole real axis by entire functions of the exponential type,” Izv. Vyssh. Ucheb. Zav. Mat., No. 2, 89–101 (1968).
5. S. M. Nikol’skii, Approximation of Functions of Several Variables and Embedding Theorems, Springer, Berlin, 1974.