West, Richard L.
Understanding interpersonal communication : making choices in changing times
Wadsworth/Clengage Learning , 2011
 Buku Teks
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
Samiul Hasan, editor
The muslim world in the 21st century: space, power, and human development
Springer, 2012
 eBooks
Cities in the 21st century / edited by Gary Gappert and Richard V. Knight
Sage Publications, 1982
 Buku Teks