editor by, Joyce Apsel, Amy Sodaro
Routledge, 2020
Buku Teks
Robertson, Arthur Henry, 1913-, author
Manchester University Press, 1992
Buku Teks
New York, N.Y. United Nations 1993,
Buku Teks
United Nations, 1988
Buku Teks
Carey, John, author
Oceana Publications, Inc, 1968
Buku Teks