On reflection of singularities of harmonic functions corresponding to the
boundary condition ${{\partial u} \mathord{\left/
{\vphantom {{\partial u} {\partial n + au}}} \right.
\kern-\nulldelimiterspace} {\partial n + au}} = 0$
@article{1183500145,
author = {Poritsky, Hillel},
title = {On reflection of singularities of harmonic functions corresponding to the
boundary condition ${{\partial u} \mathord{\left/
{\vphantom {{\partial u} {\partial n + au}}} \right.
\kern-\nulldelimiterspace} {\partial n + au}} = 0$},
journal = {Bull. Amer. Math. Soc.},
volume = {43},
number = {12},
year = {1937},
pages = { 873-884},
language = {en},
url = {http://dml.mathdoc.fr/item/1183500145}
}
Poritsky, Hillel. On reflection of singularities of harmonic functions corresponding to the
boundary condition ${{\partial u} \mathord{\left/
{\vphantom {{\partial u} {\partial n + au}}} \right.
\kern-\nulldelimiterspace} {\partial n + au}} = 0$. Bull. Amer. Math. Soc., Tome 43 (1937) no. 12, pp. 873-884. http://gdmltest.u-ga.fr/item/1183500145/