Little, A. W. Selwyn
The United States Armed Forces Institute, 1941
Buku Teks
Williamson, Harold F., author
Prentice-Hall, 1951
Buku Teks
Krooss, Herman Edward, 1912-1975, author
Prentice-Hall, 1955
Buku Teks
by Hollis Chenery...[et al.]
Oxford University Press, 1976
Buku Teks
Boix, Carles, author
Cambridge University Press, 2003
Buku Teks