@book{ title = "Wunder Spiegel", author = "Letzner, Johannes,Wittel, Martin", year = "1604", publisher = "Wittel", address = "Erffurdt", language = "ger", howpublished = "online", keywords = "Astronomie", note = "In Buch 1 vier Bücher angekündigt. - Mehr nicht erschienen?", note = "Erschienen: 1 (1604) - 2 (1604)", }