Kong, Pyong-ho, 1960-
21-segi Puksu, 2002
Buku Teks
Linder, Jane C., author
American Management Association, 2008
eBooks
Soundview Executive Book Summaries, 1989
Buku Teks
O`Neil, John R., author
McGraw-Hill, 1995
Buku Teks
Trump, Ivanka, 1981-, author
Penguin, 2017
Buku Teks