Clardy, Alan, author
Amacom, 2012
Buku Teks
Clardy, Alan, author
American Management Association, 2012
eBooks
Disney, Walt, author
Glorier International, INC, 1978
Buku Teks
Levithan, David, author
PT. Gramedia Pustaka Utama, 2018
Buku Teks
Lovelock, Christopher H., author
McGraw-Hill, 1985
Buku Teks