Weymar, Paul
A. Deutsch, 1957
Buku Teks
Odiorne, George S.
WED International, [Date of publication not identified]
Buku Teks
Barton, Greg
Saufa, IRCiSoD, LKIS, 2016
Buku Teks
Kouzes, James M.
Jossey-bass, 2012
Buku Teks
Johnson, Lyndon B. (Lyndon Bainnes)--1908-1973
An Avon Book, 1964
Buku Teks