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
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hanh tai » thanh tai, hang tai, han tai
cua viet » ca viet, hoa viet, cua vat
hanh xa » hanh va, hanh ma, hanh xu
hieu va » lieu va, hieu qua
cac toc » cac toi, cac thoi
xa hanh » xa thanh, xa khanh, va hanh
tai cua » thai cua, tai cuc, tri cua

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 xa hoi. hieu va ((cac nuoc) or (cac toc)) xa hanh tai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thi hanh xa hoi. hieu va ((cac nuoc) OR (cac toc)) xa hanh tai cua viet.
• Adding a wildcard symbol may retrieve word variants: toc sach thi hanh xa hoi. hieu va ((cac nuoc) or (cac toc)) xa hanh tai cua viet*.