Perhaps you should try some spelling variations:
thanh ca » thanh cha, thanh cac, thanh ha
thanh do » thanh de, thanh pho, thanh hoa
lang van » dang van, tang van, hoang van
cua tre » cua te, cuu tre, cua triet
cac luc » cau luc, coc luc, cac nuoc
qua cac » cua cac
van hoi » van hoa, van hoc, van hoe
sac ky » cac ky
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu ((sac ky) OR (sai ky)) lang van hoi. hieu qua cac luc va ((thanh do) or (thanh ca)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sac ky) OR (sai ky)) lang van hoi. hieu qua cac luc va ((thanh do) OR (thanh ca)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sac ky) OR (sai ky)) lang van hoi. hieu qua cac luc va ((thanh do) or (thanh ca)) cua tre*".