Potential theory, Copenhagen 1979 proceedings of a colloquium held in Copenhagen, May 14-18, 1979 / edited by C. Berg, G. Forst, and B. Fuglede. - Berg, Christian, 1944-; Forst, Gunnar, 1946-; Fuglede, Bent (Lecture notes in mathematics (Springer-Verlag) ;, 1980)