edited by Charles W. Donovan
Imperial College Press, 2015
Buku Teks
Maria Elfani
Fakultas Teknik Universitas Indonesia, 2011
Artikel Jurnal
Sørensen, Bent
Academic Press, 2007
Buku Teks
Shea, Cynthia Pollock.
Worldwatch Institute, 1988
Buku Teks
Artikel Jurnal