Msagati, Titus A. M., author
Wiley Blackwell, 2018
Buku Teks
Lawrence Erlbaum Associates , 1992
Buku Teks
Weasel, Lisa H., author
American Management Association, 2009
eBooks
Tarrant, John R.
John Wiley & Sons, 1980
Buku Teks
Emma-Jayne Abbots, Anna Lavis, Luci Attala
Routledge, 2017
Buku Teks