Werther, William B., author
Tian xia wen hua chu ban gu fen you xian gong si,, 1990
Buku Teks
Straub, Joseph T., author
American Management Association, 2000
eBooks
Planty, Earl G.
Ronald Press Company, 1948
Buku Teks
Albright, Mary
Prentice-Hall, 1997
Buku Teks
Brue, Greg, author
Media Global Edukasi, 2005
Buku Teks