Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
hanh vai » hanh vi, hanh va, hanh tai
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
ve triet » va trien, su triet
hanh cat » hanh cac, hanh cham, hanh luat
thi hanh » thi thanh
cac tuc » cac tu, cac tac, cac cuoc
cat hoi » cau hoi, sat hoi, chat hoa
cac toc » cac toi, 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) OR (cac nuoc)))) 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) OR (cac nuoc)))) xa hanh vai ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thi hanh cat hoi. hieu qua ((cac tuc) or (((cac toc) OR (cac nuoc)))) 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) OR (cac nuoc)))) xa hanh vai ve triet*.