@Book{Hirmer1930,
author  = "Hirmer, Max",
title   = "Psilophyten-Reste aus deutschem Unterdevon",
year    = "1930",
address = "München",
series  = "Sitzungsberichte",
volume  = "1930,2",
url     = "https://publikationen.badw.de/de/003383303",
}