Wasserzieher, Ernst, author
Ferd Dummlers Verlag, 1966
Buku Referensi
Kluge, Friedrich, 1856-1926, author
Walter De Gruyter, 1963
Buku Referensi
Brockelmann, Carl, author
C.F. Amerlangs verlag, 1909
Buku Klasik
Brockelmann, Carl, author
E.J. Brill, 1943
Buku Teks
Kupper, Heinz, author
Claassen Verlag, 1965
Buku Referensi