Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
cac thoi » cac toi, cac hop, cac tro
hanh cat » hanh cac, hanh cham, hanh luat
thi hanh » thi thanh
cac tuc » cac toc, cac tu, cac tac
cat hoi » cau hoi, sat hoi, chat hoa
xa hanh » xa thanh, xa khanh, va hanh
vai va » mai va, hai va, lai va
dai va » mai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach thi hanh cat hoi. hieu qua ((cac tuc) or (cac thoi)) xa hanh ((vai va) or (dai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thi hanh cat hoi. hieu qua ((cac tuc) OR (cac thoi)) xa hanh ((vai va) OR (dai va)) triet.
• Adding a wildcard symbol may retrieve word variants: toc sach thi hanh cat hoi. hieu qua ((cac tuc) or (cac thoi)) xa hanh ((vai va) or (dai va)) triet*.