Adem, Seifudein
Routledge, Taylor & Francis Group, 2018
Buku Teks SO
Kirshner, Jonathan
Princenton University Press, 1995
Buku Teks SO
edited by G. John Ikenberry
Cambridge University Press, 2014
Buku Teks SO
Sharp, Walter R.
Holt, Rinehart and Winston, 1944
Buku Teks
D`anieri, Paul J., 1965-
Cengage Learning, 2017
Buku Teks SO