edited by Frank N. Magill
Harper & Brothers, 1958
Buku Referensi
edited by S.H. Steinberg
Funk & Wagnalls, 1954
Buku Referensi
Albrecht, Gunter
Volksverlag , 1963
Buku Teks
Querido, 1949
Buku Teks
Wilpert, Gero von, author
Alfred Kroner , 1964
Buku Referensi