Perhaps you should try some spelling variations:
hay nuoc » thay nuoc, phap nuoc, nhat nuoc
dinh lai » dinh lam, dinh lap, dinh tai
te sach » toc sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va
va dinh » van dinh, va kinh, va tinh
cuu tre » cua tre, cau tren, cau treo
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang cao hoi. ((hieu va) OR (hieu qua)) hay nuoc va dinh lai ((cua te) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang cao hoi. ((hieu va) OR (hieu qua)) hay nuoc va dinh lai ((cua te) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang cao hoi. ((hieu va) OR (hieu qua)) hay nuoc va dinh lai ((cua te) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang cao hoi. ((hieu va) OR (hieu qua)) hay nuoc va dinh lai ((cua te) or (cuu tre))*.