@Book{Schumann1949,
author  = "Schumann, Winfried Otto",
title   = "Hochfrequente Schwingungserscheinungen in inhomogenen Plasmen",
year    = "1949",
address = "München",
series  = "Sitzungsberichte",
volume  = "1948,17.",
url     = "https://publikationen.badw.de/en/003383604",
}