No Inv.: 2576-2577/BD/Perp/87/2c
No Inv.: 2524-2525/BD/Perp/87/2c
Judul asli : "Inleiding tot de Wetenschapsleer"
No Inv.: 127542-127546/P/Perp/10/5c
Judul asli : "Perspective on Human Communication"
No Inv.: 2056/S/Perp/87/1c
No Inv.: 545/S/Perp/89/1c
Judul asli : "Element of Philosophy"