Bryson, Bill
I'm a stranger here myself : notes on returning to America after twenty years away
Broadway Books, 2000
 Buku Teks
Drucker, Peter Ferdinand, 1909-2005
America's next twenty years
Harper & Brothers, 1957
 Buku Teks
Davidson, Jamie S.
Indonesia: twenty years of democracy
Cambridge University Press, 2018
 Buku Teks
Celebrating twenty years with Deloitte in Indonesia
Deloitte Touche Tohmatso limited
Deloitte Touche Tohmatso limited, 2010
 Buku Referensi
Eyre, Edward John
Autobiographical narrative of residence and exploration in Australia 1832-1839 / by Edward John Eyre; edited with an introduction and notes by Jill Waterhouse
Caliban Books, 1984
 Buku Teks