Mann, Roland
McGraw-Hill , 1970
Buku Teks
Davis, R.C., author
Harper & Row, 1951
Buku Teks
The Free Press of Glencoe, 1960
Buku Teks
Gupita, Rajat, foreword
Harvard Business School, 1996
Buku Referensi
Imam Mahrudi, author
1997
UI - Tesis (Membership)