Schirmer, Alfred
Berlin Walter de Gruyter 1919
Buku Teks
Dresdowski, Gunther
Mannheim Bibliographischess 1967
Buku Teks
Mackensen, Lutz, author
Munchen Sudwest 1986
Buku Referensi
Lupson, J.P., author
Illinois: Publishing Group., 1994
Buku Referensi
Paul, Hermann, 1846-1921, author
Tubingen Max Niemeyer 1951
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