Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
tham thuc » nham thuc, pham thuc, tam thuc
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
thuc day » thuc dan, thuc vat
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
tai cua » thai cua, tri cua, dai cua
ca hoi » cau hoi, cua hoi, co hoi

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 ((ca hoi) or (xa hoi)). hieu va tham thuc day thanh ((tai cua) OR (tai cuc)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hanh ((ca hoi) OR (xa hoi)). hieu va tham thuc day thanh ((tai cua) OR (tai cuc)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi hanh ((ca hoi) or (xa hoi)). hieu va tham thuc day thanh ((tai cua) OR (tai cuc)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach thi hanh ((ca hoi) or (xa hoi)). hieu va tham thuc day thanh ((tai cua) OR (tai cuc)) triet*.