Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
thien nang » thien bang, thien dang, trien nang
thien van » thi van
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
cuu tre » cua tre, cau tren, cau treo
tu tren » tu truyen, tu tieng, tu trong
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach thien nang x hoi. thien van nam thuc va tinh va ((cuu tre) or (tu tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thien nang x hoi. thien van nam thuc va tinh va ((cuu tre) OR (tu tren)).
• Adding a wildcard symbol may retrieve word variants: toc sach thien nang x hoi. thien van nam thuc va tinh va ((cuu tre) or (tu tren))*.