@Book{Steinheil1863,
author  = "Steinheil, Carl August",
title   = "Verbesserung in der Construction der Spectral-Apparate",
year    = "1863",
address = "München",
series  = "Sitzungsberichte",
volume  = "1863,1,3",
url     = "https://publikationen.badw.de/de/003384963",
}