North-Holland Pub., 1976
Buku Teks
Andhika Oxalion
Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 2007
UI - Skripsi (Membership)
Traub, J.F.
Academic Press, 1980
Buku Teks
Boulding, Kenneth Ewart, 1910-1993
Harper, 1963
Buku Teks
Kelsen, Hans
The Lawbook Exchange, 1993
Buku Teks