Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
su triet » su viet, su tien, ve triet
sach thi » sach tai, sach thieu, sach tham
hanh tai » thanh tai, hang tai, han tai
sach thu » sach thue, sach thieu, sach tham
cua hoi » cua moi
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
tai su » tai so, tai tu, lai su

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