Loretz, Lorraine
Elsevier, 2005
Buku Teks
United Nations, 2004
Buku Teks
edited by J. Lloyd Michener, Denise Koo, Brian C. Castrucci, James B. Sprague
Oxford University Press, 2016
Buku Teks
King, Maurice H. (Maurice Henry)
Oxford University Press, 1978
Buku Teks
Strean, Herbert S.
Sage Publications, 1985
Buku Teks