Spitzer, Leo, author
Max Hueber, 1961
Buku Teks
Kluge, Friedrich, 1856-1926, author
Walter De Gruyter, 1963
Buku Referensi
Seiffert, Leslie
W. Kohlhammer, 1968
Buku Teks
Wilss, Wolfram, author
Gunter Narr, 1986
Buku Teks
Krause, F.E.A., author
Verlag Erust Reinhardt, 1924
Buku Referensi