Petro Yudytskiy, Alexandre Eremenko,
"Polynomials of the best uniform approximation to sgn(x) on two intervals"
, in Journal d'Analyse Mathématique, Nummer 114, Seite(n) 285-315, 2011, ISSN: 1565-8538
Original Titel:
Polynomials of the best uniform approximation to sgn(x) on two intervals