Bibliografi : hlm. 215-223
No Inv.: 10702-10706/P/Perp/98/5c
Judul asli : "Effective Supervision in a Factory"
No Inv.: 5039-3041/S/Perp/86/3c
No Inv.: 129422/SM/Perp/11/1c
No Inv.: 129425/SM/Perp/11/1c
No Inv.: 129432/SM/Perp/11/1c
No Inv.: 134089/PSM/Perp/13/1c