@Book{Johnsen1918,
author  = "Johnsen, Arrien",
title   = "Optisches Drehungsvermögen und Schraubungsaxen regulärer Kristalle",
year    = "1918",
address = "München",
series  = "Sitzungsberichte",
volume  = "1918,11",
url     = "https://publikationen.badw.de/en/003399176",
}