Anderson, Joyce I.
American Management Association, 2007
eBooks
Yuni Jie
Gramedia Pustaka Utama, 2007
Buku Teks
Design Media Publishing Limited, 2010
Buku Referensi
Swanson, Bettye B.
Macmillan, 1981
Buku Teks
Johnson, Joyce Young
Lippincott , 1998
Buku Teks