Hart, Albert Gailord, 1909-, author
Twentieth Century Fund, 1953
Buku Teks
edited Norman J. Glickman
John Hopkins University Press, 1980
Buku Teks
Lieu, D.K.
Rutgers University Press, 1948
Buku Teks
edited by William R. Cline and Sidney Weintraub
Washington, D.C. , Brooklins Institution
Buku Teks
Adams, E. Sherman, author
Ronald Press, 1950
Buku Teks