Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
thanh vi » thanh va, thanh ve, nhanh vi
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang co » nang cao, nang doc, nang noi
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang co hoi. ((hieu vien) or (hieu hien)) cac dan ca ((thanh vi) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang co hoi. ((hieu vien) OR (hieu hien)) cac dan ca ((thanh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang co hoi. ((hieu vien) or (hieu hien)) cac dan ca ((thanh vi) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang co hoi. ((hieu vien) or (hieu hien)) cac dan ca ((thanh vi) OR (hanh vi)) cua tre*.