Simon and Schuster, 1962
Buku Teks
Brokings Institution, 1950
Buku Teks
Harrison, W.E.C., author
Oxford University Press, 1957
Buku Teks
edited by Robbin F. Laird and Erik P. Hoffman
Aldine de Gruyter, 1986
Buku Teks
Thomson, Charles A.
Indiana University Press, 1963
Buku Teks