Locke, John
J.M.Dent & Sonds, 1960
Buku Teks
World Bank, 2002
Buku Teks
Information , 1983
Buku Referensi
Muh Kadarisman
Faculty of Social and Political Sciences, Universitas Muhammadiyah Jakarta, 2012
Artikel Jurnal
Muh Tang Abdullah
2014
Artikel Jurnal