The University of Auckland, 1999
Buku Teks
Imam Yudotomo
Centre for Social-Democratic Studies, 2000
Buku Teks
Asmarawati Handoyo, author
Universitas Muhammadiyah Yogyakarta, Department of Government and Study, 2016
Artikel Jurnal
Kerstiens, Thom
Praeger , 1966
Buku Teks
Good, Yohn M
Heath, 1970
Buku Teks