Fatmah, author
Gramedia Pustaka Utama, 2013
Buku Teks
Richman, Larry, author
[American Management Association, ], 2002
eBooks
Christensen, Howard B., author
Hoghton Mifflin, 1977
Buku Teks
Sartika Kurniali, author
PT Gramedia, 2009
Buku Teks
Drago, Carl, author
Blackwell Publishing, 2007
Buku Referensi