Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
hang tai » hang va, dung tai
thi hang » thi hanh, thi nang, thi hong
vat hang » van hang, dat hang, va hang
tai cua » thai cua, tai cuc, tri cua
va tham » van tham, va cham, va thanh
tu sach » thu sach, te sach, tu cach
hieu va » lieu va, hieu qua
cua hoi » cua moi
su sach » so sach, vu sach

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