Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » hoc sach, thuoc sach, nuoc sach
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
doc sach » hoc sach, nuoc sach, dac sac
thi hanh » thi thanh
xa thanh » va thanh, ha thanh, ta thanh
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
hanh ca » hanh cac, hanh cat, hanh cua
su viet » so viet
ca hoi » cau hoi, cua hoi, xa hoi
dai su » dai sua, dai so, dan su

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