Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
duc ban » duc tan, dua ban, duc man
hieu va » lieu va, hieu qua
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
su sac » su sach, su cac, su xac

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 ky nang ma hoi. ((hieu ve) or (hieu va)) cam ((duc ban) or (duc van)) thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ma hoi. ((hieu ve) OR (hieu va)) cam ((duc ban) OR (duc van)) thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ma hoi. ((hieu ve) or (hieu va)) cam ((duc ban) or (duc van)) thanh dai cua tre*.