Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
nam truc » nam truoc, nam thuc, nam trung
truc van » truc va, thuc van, truc ban
van hanh » van thanh, ban hanh, van anh
cao hoi » cau hoi, co hoi, cao hoc
cua tre » cua te, cuu tre, cua triet
su cac » tu cac, su cao, su can
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su cac ky nang cao hoi. ((hieu van) or (lieu va)) nam truc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su cac ky nang cao hoi. ((hieu van) OR (lieu va)) nam truc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su cac ky nang cao hoi. ((hieu van) or (lieu va)) nam truc van hanh vi cua tre*.