Sharp estimates of approximation in Lp by functions of the form φ(x) + ψ(y)
English version (Springer): Ukrainian Mathematical Journal 41 (1989), no. 6, pp 700-702.
Citation Example: Pichugov S. A. Sharp estimates of approximation in Lp by functions of the form φ(x) + ψ(y) // Ukr. Mat. Zh. - 1989. - 41, № 6. - pp. 815-818.
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