Jones, F.C.
American Council Instiutute of Pacific Relations, 1940
Buku Teks
Willoughby, Westel W., author
John Hopkins Press, 1927
Buku Teks
Steel, Robert George Douglas, 1917-, author
McGraw-Hill, 1960
Buku Teks
Prakash, Om, author
Frederick A. Praeger, 1962
Buku Teks
Jaschke, H.A.
London : Routledge & Kegan Paul Ltd., 1949.
Buku Teks