No Inv.: 133540/S/Perp/12/1c
No Inv.: 136057,136058/SM/Perp/13/2c
Bibliografi : hlm. 207-210 No Inv.: 142093-142097/P/Perp/14/5c
Bibliografi : hlm. 333-343 No Inv.: 138898-138899/P/Perp/14/2c
No Inv.: 146986/P/Perp/15/1c
No Inv.: 10871-10880/P/Perp/98/10c
Judul asli : "The Skill of Communicating"
No Inv.: 112896/P/Perp/08/1c
No Inv.: 32298,32356,32367,32343,32330,32347,32326,32261,32316,32340,32335,32336,32329,32359,32280,32338,32362,32277,32344,32333,32272,32278,32274,32331,32350,32271.32334/P/Perp/96/32
Judul asli : "Personal Letters for Business People"