Federal Republic
Wiesbaden : Wiesbadener Graphische Betriebe GmbH, 1977
Buku Referensi
Kohlhammer, 1961
Buku Teks SO
Heyde, Wolfgang
C.F. Muller Juristischer Verlag, 1999
Buku Teks
edited by The Linguistic Section of the Foreign Office of the Federal Republic of Germany
Press and Information Office, 1973
Buku Teks SO
Pergamon Press, 1980
Buku Teks