Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
dung sai » dung tai, dung va, dung dat
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
hieu le » hieu ve, hieu ly, tieu le
hieu he » hieu ve, hiem he, hieu kem
xa dung » xay dung, xa dong, va dung
sai cua » dai cua, hai cua, lai cua
thu xa » thu xac, thu ha, thu xe

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. ((hieu hien) OR (((hieu le) OR (hieu he)))) nam thu xa dung sai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang cao hoi. ((hieu hien) or (((hieu le) OR (hieu he)))) nam thu xa dung sai cua viet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoi. ((hieu hien) or (((hieu le) OR (hieu he)))) nam thu xa dung sai cua viet*.