No Inv.: 126219/P/perp/10/1c
Bibliografi : hlm. 139-149
Bibliografi : hlm. 60
No Inv.: 11643-11645/P/Perp/93/3c~10803-10804/P/Perp/91/2c
Judul asli :"The Essence of information systems"
No Inv.: 10663-10667/P/Perp/92/5c
No Inv.: 1739-1743/P/Perp/95/5c~11951-11960/P/Perp/98/10c
No Inv.: 131/AF/Perp/90/1c