@Book{Hofmann1928,
author  = "Hofmann, Joseph Ehrenfried",
title   = "Über algebraische, insbesondere lineare Integrale algebraischer Differentialgleichungen 1. Ordnung 1. Grades",
year    = "1928",
address = "München",
series  = "Sitzungsberichte",
volume  = "1928,21",
url     = "https://publikationen.badw.de/en/003383259",
}