@Book{ElsterGeitel1903,
author  = "Elster, Julius and Geitel, Hans",
title   = "Über die radioaktive Emanation in der atmosphärischen Luft",
year    = "1903",
address = "München",
series  = "Sitzungsberichte",
volume  = "1903,11",
url     = "https://publikationen.badw.de/en/003394472",
}