@book { Diequivalenzstrung, title = "Die Äquivalenzstörung", subtitle = "Ein Beitrag zur Lehre von der Geschäftsgrundlage", author = "Philipp {Härle}", year = "1995", publisher = "Peter Lang Verlag", address = "Berlin, Germany", url = "https://www.peterlang.com/document/1116219" }