No Inv.: 106409/P/Perp/06/1c~107235/S/Perp/06/1c
Judul asli : "The Essence of Leadership"
No Inv.: 78600-7809/01/10c
Bibliografi : hlm. 103-106No Inv.: 135485/SM/Perp/13/1c~135640/SM/Perp/13/1c
No Inv.: 139-140/BD/Perp/86/2c
Jilid 1 : ed. ke-2; jilid 2 : ed. ke-3
No Inv.: 403-404/BD/Perp/86/2c
Bibliografi : hlm. 131-134No Inv.: 5071/P/Perp/14/1c
No Inv.: 104640/P/Perp/06/1c