Huber, Diane L., author
Elsevier Saunders, 2005
Buku Teks
Leutholtz, Brian C., author
CRC Press Taylor &Francis Group, 2011
Buku Teks
Taylor, James, author
American Management Association, 2006
eBooks
Stewart, Rosemary, author
Macmillan, 1993
Buku Teks
Smith, Anthelyn Jean, author
Lippincott , 1990
Buku Teks