Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
va thieu » va thiet, va hieu, va tieu
thu sach » tu sach, thuat sach, thuoc sach
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
thuc va » thuc vat, thuc dan
dan vai » dan va, dan tai, dan vat
su sach » so sach, vu sach
vai va » mai va, dai va, hai va

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) or (thu sach)) ky nang cao hoi. hieu va pham ((thuc va) OR (thuc day)) dan vai va thieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) ky nang cao hoi. hieu va pham ((thuc va) OR (thuc day)) dan vai va thieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu sach)) ky nang cao hoi. hieu va pham ((thuc va) OR (thuc day)) dan vai va thieu".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) ky nang cao hoi. hieu va pham ((thuc va) OR (thuc day)) dan vai va thieu*.