@Book{Stumpf1891,
author  = "Stumpf, Carl",
title   = "Psychologie und Erkenntnistheorie",
year    = "1891",
address = "München",
series  = "Abhandlungen",
volume  = "19,[7] : 2. Abth.",
url     = "https://publikationen.badw.de/en/003205014",
}