West, Richard L.
Understanding interpersonal communication : making choices in changing times
Wadsworth/Clengage Learning , 2011
 Buku Teks SO
Human geography : issues for 21st century
Peter Daniels [and others]
Prentice-Hall, 2001
 Buku Teks
Tatum Syarifah Adiningrum
It right : the importance of communication skills to 21st century educational leaders
[Publisher not identified], 2011
 Artikel Jurnal
The muslim world in the 21st century: space, power, and human development
edited by Samiul Hasan
Springer, 2012
 eBooks
Asia in the 21st century: emerging thoughts & philosophy of an Asian century / edited by Abdul Razak Abdullah Baginda
Pelanduk Publications, 1996
 Buku Teks SO