McGraw-Hill, 2003
Buku Teks
Likert, Rensis
McGraw-Hill, 1976
Buku Teks
Jackson, Alastair, author
Allen & Unwin , 2000
Buku Teks
Dobson, Michael Singer, author
[American Management Association, ], 2000
eBooks
Vacca, John R., editor
Syngress, 2014
eBooks