@Book{Wirtinger1942,
author  = "Wirtinger, Wilhelm",
title   = "Zur Theorie der konformen Abbildung mehrfach zusammenhängender ebener Flächen",
year    = "1942",
address = "Berlin",
series  = "Abhandlungen",
volume  = "1942,4",
url     = "https://publikationen.badw.de/en/003537165",
}