Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
hanh cat » hanh cac, hanh cham, hanh luat
hanh vai » hanh vi, hanh va, hanh tai
ve triet » va trien, su triet
cat hoi » cau hoi, sat hoi, chat hoa
cac tuc » cac tu, cac tac, cac nuoc
cac toc » cac toi, cac nuoc, cac thoi
xa hanh » xa thanh, xa khanh, va hanh
vai ve » va ve, dai ve, vai 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 toc)) xa hanh vai ve 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 toc)) xa hanh vai ve triet.
• Adding a wildcard symbol may retrieve word variants: toc sach thi hanh cat hoi. hieu qua ((cac tuc) or (cac toc)) xa hanh vai ve triet*.