United Nations Centre for Human Settlements (Habitat), 1991
Buku Referensi
Banks, Ferdinad E.
Kluwer Academic, 2000
Buku Teks SO
Laitos, Jan G.
West Publishing, 1992
Buku Teks
Chapman, J.D.
Longman Scientific & Technical, 1989
Buku Teks SO
Sihombing, Adolf Leopold S.M.
Badan Penelitian dan Pengembangan Energi dan Sumber Daya Mineral, 2016
Artikel Jurnal