Hoover, J. Edgar (John Edgar), 1895-1972
Holt, 1958
Buku Teks
Harry Siswanto
W.W. Norton & Company. INC, 1961
Buku Teks SO
Martin, Dick
American Management Association, 2007
eBooks
McIntosh, Jane
Checkmark Books, 1999
Buku Referensi
Orlov, Darlene
[American Management Association;, ], 1999
eBooks