Jenks, C. Wilfred
Oceana, 1963
Buku Teks
Corbett, Michael,
Longman, 1982.
Buku Teks
Miles, Malcolm
[publisher not identified], 2000
Buku Teks
Sumitro Joyohadikusumo
Institute for Economic and Social Research, Education, and Information, 1977
Buku Teks
Buku Teks