Bisson, T.A.
Macmillan, 1945
Buku Teks SO
Hubbard, G.E.
International Secretariat Institute of Pasific Relations, 1943
Buku Teks
Bisson, T.A.
International Secretariat Institute of Pasific Realtions , 1945
Buku Teks
Millard, Thomas F.
Fisher Unwin, 1908
Buku Teks SO
Stocholm, 1958
Buku Teks