@Book{Mittelstaedt1960,
author  = "Mittelstaedt, Peter",
title   = "Untersuchungen zur Quantenlogik",
year    = "1960",
address = "München",
series  = "Sitzungsberichte",
volume  = "1959,15",
url     = "https://publikationen.badw.de/de/003384024",
}