On the inverse mean value property of harmonic functions on ellipses and best harmonic \(L^ 1\)-approximation. (English) Zbl 0858.31002
Müller, Manfred W. (ed.) et al., Approximation theory. Proceedings of the 1st international Dortmund meeting IDoMAT 95 held in Witten, Germany, March 13-17, 1995. Berlin: Akademie Verlag. Math. Res. 86, 179-187 (1995).
Reviewer: B.Kjellberg (Stockholm)