Spaeth, Harold J.
W.H.Freeman and Company, 1976
Buku Teks
Rostow, Eugene V., author
Yale University Press, 1963
Buku Teks
Lamparello, Adam, author
NY Routledge, 2017
Buku Teks
Clayton, James E., author
E.P. Dutton, 1964
Buku Teks
Carr, Robert K., author
Rinehart, 1942
Buku Teks