Robertson, Ben, author
University of queensland press, 2010
Buku Referensi
Artikel Jurnal
Christina Lipuringtyas Rudatin, author
Universitas Indonesia, 2006
UI - Tesis (Membership)
Simorangkir, Ignatia Oktavia, author
2013
UI - Skripsi (Membership)
Hughes, Michael, author
McGraw-Hill, Higher Education, 2009
Buku Teks