Haftman, Werner, author
Frederick A. Praeger, Pub., 1960
Buku Referensi
Franke, Wolfgang, author
University of South Carolina Press, 1981
Buku Teks
Keylor, William R., 1944-, author
Oxford University Press, 1996
Buku Teks
Salem Press , 1992
Buku Referensi
Salem Press , 1992
Buku Referensi