@Book{Finsterwalder1888,
author  = "Finsterwalder, Sebastian",
title   = "Katoptrische Eigenschaften der Flächen 2. Grades",
year    = "1888",
address = "München",
series  = "Sitzungsberichte",
volume  = "1887,4",
url     = "https://publikationen.badw.de/en/003392464",
}