Cetron, Marvin J.
Encounters with the future : a forecast of life into the 21st century
McGraw-Hill, 1982
 Buku Teks SO
Hammond, Allen L.
Which world ? scenarios for the 21st Century : global destinies, regional choices
Earthscan Publications, 1998
 Buku Teks SO
Hirst, Paul
War and power in the 21st century: perang dan kekuatan di abad ke-21: konflik militer, negara dan sistem internasional
Murai Kencana, 2004
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Asia in the 21st century: emerging thoughts & philosophy of an Asian century / edited by Abdul Razak Abdullah Baginda
Pelanduk Publications, 1996
 Buku Teks SO
Hawken, Paul
Natural capitalism : creating the next industrial revolution / Paul Hawken, Amory Lovins, L. Hunter Lovins
Little, Brown and company , 1999
 Buku Teks SO