@Book{Pfaff1817,
author  = "Pfaff, Carl Wilhelm Andreas",
title   = "Annotationes ad theoriam atque historiam perturbationum coelestium pertinentes",
year    = "1817",
address = "München",
series  = "Denkschriften",
volume  = "5,[8] = 6 : Classe der Mathematik und Naturwissenschaften",
url     = "https://publikationen.badw.de/de/017903461",
}