Nakai, Mitsuru The equation \(\Delta u=Pu\) on the unit disk with almost rotation free \(P\geq 0\). (English) Zbl 0229.31002 J. Differ. Equations 11, 307-320 (1972). MSC: 31A25 30F20 PDFBibTeX XMLCite \textit{M. Nakai}, J. Differ. Equations 11, 307--320 (1972; Zbl 0229.31002) Full Text: DOI
Glasner, Moses Dirichlet mappings of Riemannian manifolds and the equation \(\Delta u = Pu\). (English) Zbl 0235.31009 J. Differ. Equations 9, 390-404 (1971). MSC: 31C05 31C12 PDFBibTeX XMLCite \textit{M. Glasner}, J. Differ. Equations 9, 390--404 (1971; Zbl 0235.31009) Full Text: DOI