@book{id_7854,
author = "Vogel, August",
title = "Beitrag zur Kenntniss des Copal's",
year = "1881",
address = "München",
publisher = "Franz in Komm.",
series = "Sitzungsbericht der Bayerischen Akademie der Wissenschaften",
volume = "1881,8.",
url = "http://publikationen.badw.de/de/003395071",
}