@book { Kompetenzensichtbarmachen, title = "Kompetenzen sichtbar machen", subtitle = "Zum Einsatz von Kompetenzportfolios in Waldorfschulen", author = "Michael {Brater} and Dieter {Haselbach} and Antonia {Stefer}", year = "2010", publisher = "Peter Lang Verlag", address = "Berlin, Germany", url = "https://www.peterlang.com/document/1135539" }