Yates, Brock
Empire Books, 1983
Buku Teks
Pelfrey, William, author
American Management Association, 2006
eBooks
Harcourt , 1964
Buku Teks
Phillips, Charles F., author
University of North Carolina , 1963
Buku Teks
Syarafi Auzan Mu`min, author
2016
UI - Skripsi (Membership)