Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
thanh tai » thanh hai, thanh toan, doanh tai
va triet » va thiet, va trien, ve triet
thi hang » thi hanh, thi nang, thi hong
hanh tai » hang tai, han tai, hinh tai
sach thi » sach thu, sach tai, sach thieu
thuc va » thuc vat, thuc dan, thuc day
te sach » toc sach
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
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: te sach thi hang ((ca hoi) or (xa hoi)). hieu va tham thuc va ((hanh tai) OR (thanh tai)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi hang ((ca hoi) OR (xa hoi)). hieu va tham thuc va ((hanh tai) OR (thanh tai)) va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi hang ((ca hoi) or (xa hoi)). hieu va tham thuc va ((hanh tai) OR (thanh tai)) va triet*".