Levy, John M., author
Routledge, 2013
Buku Teks
Levy, John M., author
Prentice-Hall, 1991
Buku Referensi
Dwiyanti Kusumaningrum, author
Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2012
UI - Skripsi (Open)
The Hague Ministry of Foreign Affairs , 1994
Buku Teks
Golany, Gideon S., author
John Wiley & Sons, 1995
Buku Teks