Patterson, Thomas E., author
McGraw-Hill, 203
Buku Teks
Tocqueville, Alexis De, author
David Campbell Publishers, 1994
Buku Referensi
Konkrad-Adenauer-Stiftung, editor
Konkrad-Adenauer-Stiftung, 2007
Buku Teks
Barbu, Zevedei, author
Routledge , 1965
Buku Teks
Catt, Helena, author
Routledge , 1999
Buku Teks