@Book{Perron1906,
author  = "Perron, Oskar",
title   = "Über die Konvergenz periodischer Kettenbrüche",
year    = "1906",
address = "München",
series  = "Sitzungsberichte",
volume  = "1905,19",
url     = "https://publikationen.badw.de/en/003388826",
}