C.L. van Langenhuysen, 1918
Buku Teks
Keeton, George W., 1902-1989., editor
Stevans & Sons , 1949
Buku Teks
Bisson, T.A., author
The Foreign Policy Association , 1941
Buku Teks
Harcourt-Smith, Simon
Alfred A. Knopf, 1942
Buku Teks
edited by George H. Blakeslee
Steven, 1949
Buku Teks