Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
thanh vi » hanh vi, thanh va, thanh ve
so sach » so sanh, bo sach, co sach
thu ban » thu hang
cac thu » cach thuc, cac thoi
hieu ve » hieu va
lang xa » lang ha, dang xay, lang van
cuu tre » cua tre, cau tren, cau treo
y lang » o lang, _ lang, tay lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y lang xa hoi. ((hieu ve) or (hieu van)) cac thu ban thanh vi ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y lang xa hoi. ((hieu ve) OR (hieu van)) cac thu ban thanh vi ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: so sach y lang xa hoi. ((hieu ve) or (hieu van)) cac thu ban thanh vi ((dua tren) or (cuu tre))*.