Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi tang » thi trang, thai tang, thi nang
nam thuc » nam thuoc, am thuc, nam tu
day hanh » day nhanh, day thanh, dao hanh
va triet » va thiet, va trien, ve triet
so sach » so sanh, bo sach, co sach
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
ma hoi » mai hoi, xa hoi, ma hoa
vi va » vi van, vai va, vu va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach thi tang ma hoi. ((hieu ve) or (hieu qua)) ((nam thuc) OR (nam thu)) day hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thi tang ma hoi. ((hieu ve) OR (hieu qua)) ((nam thuc) OR (nam thu)) day hanh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thi tang ma hoi. ((hieu ve) or (hieu qua)) ((nam thuc) OR (nam thu)) day hanh vi va triet".
• Adding a wildcard symbol may retrieve word variants: so sach thi tang ma hoi. ((hieu ve) or (hieu qua)) ((nam thuc) OR (nam thu)) day hanh vi va triet*.