Perhaps you should try some spelling variations:
dam thuc » am thuc, dan thuc, nam thuc
hanh may » hanh ma, hanh mau, hanh ngay
va thieu » va thiet, va hieu, va tieu
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
va hanh » van hanh, va thanh, va danh
ma hoi » mai hoi, xa hoi, ma hoa
dam tu » nam tu, cam tu, tam tu
may va » may vi, day va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ma hoi. lieu va ((dam thuc) or (dam tu)) va hanh may va thieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. lieu va ((dam thuc) OR (dam tu)) va hanh may va thieu.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoi. lieu va ((dam thuc) or (dam tu)) va hanh may va thieu*.