No Inv.: 121/H/Perp/88/1c
No Inv.: 10149-10150/P/Perp/92/2c
No Inv.: 2792-2793/BD/Perp/87/2c
No Inv.: 373/YA/Perp/88/1c
Judul asli : "Neiburge, Understanding our Environment".
Bibliografi : hlm. 280-284 No Inv.: 128166/SM/Perp/10/1c~134944/SM/Perp/13/1c~134759/SM/Perp/13/1c~135527/SM/Perp/13/1c~135238/SM/Perp/13/1c