@Article{JPDE-28-197,
author = {Kong , Shengli 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 = {http://global-sci.org/intro/article_detail/jpde/5110.html}
}