@Book{Fedorov1909,
author  = "Fedorov, Evgraf S.",
title   = "Syngonielehre",
year    = "1909",
address = "München",
series  = "Abhandlungen",
volume  = "Bd. 23, Abth. 1 = [1]",
url     = "https://publikationen.badw.de/en/003071196",
}