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
Bryson, Bill
I'm a stranger here myself : notes on returning to America after twenty years away
Broadway Books, 2000
 Buku Teks
Celebrating twenty years with Deloitte in Indonesia
Deloitte Touche Tohmatso limited
Deloitte Touche Tohmatso limited, 2010
 Buku Referensi
China after five years of war prepared under the auspices of the Ministry of Information of the Republic of China
Chinese News Service, 1942
 Buku Teks