Dobson, Ann
How to Communicate at work
grolier international, 1999
Buku Teks
How Networks Work
Buku Teks
Hospitals : what they are and how they work
Donald J. Griffin, editor
Jones & Bartlett Learning, 2011
Buku Teks
Basic machines and how they work
prepared by Bureau of Naval Personnel
Dover Publications, 1997
Buku Teks
Parker, Steve
How things work
Parragon, 2000
Buku Referensi