Sri Wulandari
Perubahan determinator grup nominal bahasa jawa dialek Cirebon dalam teks abad ke 18 abad ke 21 = Determiner nominal group change in Cirebonese dialect based on the 18th century text until 21st
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2014
 UI - Tesis (Membership)
Harman, Willis
Global mind change : the promise of the 21st century
Berrett-Koehler , 1998
 Buku Teks
F.X. Supartono
Modern trend of bridges towards the 21st century
Fakultas Teknik Universitas Indonesia, 1997
 UI - Laporan Penelitian
Mayall, James B. L.
Towards the new horizon : world order in the 21st century
Standard Publishers, 2009
 Buku Teks
Grenville, J.A.S.
A history of the world : from the 20th to the 21st century
Routledge, 2005
 Buku Teks