Kramer, X.E.
T.M.C. Asser Press, 2012
eBooks
Evi Nurvidya Arifin
[publisher not identified], 2006
Buku Klasik
Appleby, Pauline
Glorier International, 2001
Buku Referensi
Lambe, Patrick
Chandos Publishing, 2007
Buku Teks
Chorafas, Dimitris N.
Macmillan, 1974
Buku Teks