Lovel, John P
Macmillan, 1985
Buku Teks
Bemis, Samuel Flagg, 1891-1973, author
Alfred A. Knopf, 1949; 1956
Buku Teks
Departement of Stetes Based, 1949
Buku Teks
edited by Raymond Dennett
World Peace Foundation, 1948
Buku Teks
Quandt, William B.
The Brooking Institution, 1981
Buku Teks