Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, hieu ve
nam truc » nam truoc, nam trung, nam thuoc
nam thuc » nam thuoc, am thuc, nam thu
thanh vi » hanh vi, thanh va, thanh ve
cao hoi » cau hoi, co hoi, cao hoc
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
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 sac ky nang cao hoi. ((hieu van) or (lieu va)) ((nam truc) OR (nam thuc)) van thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang cao hoi. ((hieu van) OR (lieu va)) ((nam truc) OR (nam thuc)) van thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang cao hoi. ((hieu van) or (lieu va)) ((nam truc) OR (nam thuc)) van thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang cao hoi. ((hieu van) or (lieu va)) ((nam truc) OR (nam thuc)) van thanh vi cua tre*.