Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
doc sach » hoc sach, toc sach, nuoc sach
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
xa thanh » va thanh, ha thanh, ta thanh
so triet » su triet, so thiet, bo triet
hanh ca » hanh cac, hanh cat, hanh cua
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
ca hoi » cau hoi, cua hoi, xa hoi

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

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