Bibliografi : hlm. 249-251 No Inv.: 135414/SM/Perp/13/1c
Bibliografi : hlm. 131-137 No Inv.: 136465/SM/Perp/14/1c
No Inv.: 139760, 139761/P/Perp/14/2c
Bibliografi : hlm. 239-256 No Inv.: 138705, 138706/P/Perp/14/2c
No Inv.: 140922, 140923/P/Perp/14/2c
No Inv.: 3451/P/99/1c
Judul asli : "Introduction to Work Study"
No Inv.: 111276-111280/P/Perp/07/5c~115781-115783/P/Perp/09/3c~127282-127286/P/Perp/10/5c
BIbliografi : hlm. 177-180
Bibliografi: hal 129-136