Kreller, Susan
You can't see the elephants
Putnam's Sons, an imprint of Penguin Group , 2015
 Buku Teks
Cleary, Jon
You can't see round corners
Collins Publishers Australia, 1947
 Buku Teks
Muthahhari, Murtadha
Stop anarkisme
Alhuda, 2006
 Buku Teks
King, MArtin Luthre
Why we can't wait / Martin Luthern King
Harper & Row pub, 1964
 Buku Teks
Walton, Donald
Are you communicating?: you can't manage without it
McGraw-Hill , 1989
 Buku Teks SO