Tambunan, Emil H., author
Indonesia Publishing House, 2007
Buku Teks
Schuller, Robert H., author
Gunung Mulia, 1986
Buku Teks
Canterucci, Jim, author
American Management Association;, 2005
eBooks
Tingley, Judith C., author
American Management Association;;, 1996
eBooks
Scott, Kim, author
Pan Books, 2019
Buku Teks