Perhaps you should try some spelling variations:
dang xay » dang van, van xay
doan thi » dan thi, doanh tai, hoang thi
tu sach » thu sach, su sach, te sach
cac tho » cac thoi, cac thu, cac thi
sach cu » sach cua, sach tu, sach uu
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
xay hoi » xa hoi, tay hoi, cay phoi
cu dang » cua dang, su dang, vu dang

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach cu dang xay hoi. hieu ve ((cac tho) OR (cac tro)) va ((don vi) or (doan thi)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach cu dang xay hoi. hieu ve ((cac tho) OR (cac tro)) va ((don vi) OR (doan thi)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach cu dang xay hoi. hieu ve ((cac tho) OR (cac tro)) va ((don vi) or (doan thi)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach cu dang xay hoi. hieu ve ((cac tho) OR (cac tro)) va ((don vi) or (doan thi)) cuu tre*.