Bookchin, Murray
Black Rose Books, 1990
Buku Teks SO
I Wayan Suwira Satria
Departemen kewilayaan FIB Universitas Indonesia, 2009
Artikel Jurnal
edited by Timothy D.J. Chappell
Edinburgh University, 1997
Buku Teks SO
Maritain, Jacques
Philosophical Library, 1951
Buku Teks SO
Koren, Henry J.
Duquesne University, 1960
Buku Teks SO