Bibliografi : hlm. 452-455
No Inv.: 126682-126686/P/Perp/10/5c
No Inv.: 139184,139185/P/Perp/14/2c
No Inv.: 139168,139169/P/Perp/14/2c
Bibliografi : hlm. 121-126
No Inv.: 82/PSM/Perp/97/1c~85020-85024/P/Perp/FIS/03/5c~137660/SM/Perp/14/1c
Judul asli :"Business Professional communications"
Bibliografi : hlm. 333-335 No Inv.: 141406-141410/P/Perp/14/5c