Andrew Millie, Dilip K. Das, editor
CRC Press, Taylor & Francis Group, 2008
Buku Teks
UNDP-ESCAP , 1989
Buku Teks
edited by Louis Henkin
Spectrum, 1961
Buku Teks
edited by Fiona Sim, Martin McKee
McGraw-Hill, 2011
Buku Teks
Hill, John W.
Prentice-Hall, 1975
Buku Teks