@Article{JPDE-28-3,
author = {Shengli, Kong and Xu, Jinju},
title = {A Remark on the Level Sets of the Graph of Harmonic Functions Bounded by Two Circles in Parallel Planes},
journal = {Journal of Partial Differential Equations},
year = {2015},
volume = {28},
number = {3},
pages = {197--207},
abstract = { In this paper,we find two auxiliary functions andmake use of themaximum principle to study the level sets of harmonic function defined on a convex ring with homogeneous Dirichlet boundary conditions in $\mathbb{R}^2$. In higher dimensions, we also have a similar result to Jagy's.},
issn = {2079-732X},
doi = {https://doi.org/10.4208/jpde.v28.n3.1},
url = {https://global-sci.com/article/88277/a-remark-on-the-level-sets-of-the-graph-of-harmonic-functions-bounded-by-two-circles-in-parallel-planes}
}