Downs, Lisa J.
Listening skills training
American Society for Training & Development, 2008
 eBooks
Scott, John
Effective management skills : what is a manager?
Spere British Institute of Management, 1984
 Buku Teks
Munter, Mary
Guide to managerial communication: effective business writing and speaking
Prentice-Hall, 1982
 Buku Referensi
Ellis, Carol W.
Management skills for new managers
[American Management Association, ], 2005
 eBooks
Burley-Allan, Madelyn
Listening: the forgotten shill
John Wiley & Sons, 1982
 Buku Teks SO