Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
cua tre » cua te, cuu tre, cua triet
duc ban » duc tan, duc van, duc man
ke mang » ke nang, ke trang
may thi » may thoi, day thi, mai thi
hieu ve » hieu van
hieu va » lieu va, hieu qua
dua ban » dia ban, cua ban, qua ban
su sac » su sach, su cac, su xac
sac ke » tac ke, sac ky, cac ke

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ke mang may thi. ((hieu ve) or (hieu va)) cam ((duc ban) OR (dua ban)) thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ke mang may thi. ((hieu ve) OR (hieu va)) cam ((duc ban) OR (dua ban)) thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ke mang may thi. ((hieu ve) or (hieu va)) cam ((duc ban) OR (dua ban)) thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ke mang may thi. ((hieu ve) or (hieu va)) cam ((duc ban) OR (dua ban)) thanh dai cua tre*.