Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thi hanh » thi thanh
van hanh » van thanh, ban hanh, van anh
sach thi » sach thu, sach tai, sach thieu
vai cua » dai cua, hai cua, lai cua
va hanh » va thanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
hieu ve » hieu van
hanh xa » hanh va, hanh ma, hanh xu
hieu va » lieu va, hieu qua

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 thi hanh xa hoi. ((hieu ve) or (hieu va)) am thuc ((va hanh) OR (van hanh)) vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hanh xa hoi. ((hieu ve) OR (hieu va)) am thuc ((va hanh) OR (van hanh)) vai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi hanh xa hoi. ((hieu ve) or (hieu va)) am thuc ((va hanh) OR (van hanh)) vai cua viet*".