Langford, Beverly Y., author
American Management Association, 2005
eBooks
Brennan, Lynne, author
Platkus, 1991
Buku Teks
Robinson, David, author
Gramedia Pustaka Utama, 1996
Buku Teks
Grant-Sokolosky, Valerie
Dabara Bengawan, 1991
Buku Teks
Asiapac Books, 2002
Buku Teks