Browne, G.S., author
F.W. Chesire, 1960
Buku Teks
Woytinsky, W.S.
The Twentieth Century Fund, 1953
Buku Teks
Keyfitz, Nathan, author
The University of Chicago Press, 1968
Buku Teks
Bouvier, Leon F., author
Seven Lucks Press, 1999
Buku Teks
United Nations, 1979
Buku Teks