Miller, Laurence, 1951-
From difficult to disturbed: understanding and managing dysfunctional employees
American Management Association, 2008
 eBooks
Liff, Stewart
Managing government employees: how to motivate your people, deal with difficult issues, and achieve tangible results
American Management Association, 2007
 eBooks
Hutchinson dictionary of difficult words
edited by John Ayto
Helicon, 1994
 Buku Referensi
Boyd, Martin
A difficult young man
Lansdowne Press, 1974
 Koleksi Publik
Treating difficult personality disorders
edited by Michael Rosenblith and Irvin D. Yalom
Jossey-Bass, 1997
 Buku Teks SO