Perhaps you should try some spelling variations:
sang tai » hang tai, tang tai, sang than
sang tao » hang tai
hieu ve » hieu va, hieu van
cac toc » cac toi, cac nuoc, cac thoi
nang ma » tang ma, sang ma, nang cao
va sang » van sang, vua sang, va nang
cuc te » cua te, cuc tieu
toc va » hoc va, toc ta, tuc va
su xac » pu xac, su cac
ve cac » va cac, vien cac
xac ky » cac ky, sac ky, bac ky
thue » thu, thuc, thuy

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

• Performing a fuzzy search may retrieve terms with similar spellings: su xac ky ((nang ma) or (sang tao)) hoi. hieu ve cac toc va sang tai ((cuc te) OR (cuc thue))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su xac ky ((nang ma) OR (sang tao)) hoi. hieu ve cac toc va sang tai ((cuc te) OR (cuc thue)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su xac ky ((nang ma) or (sang tao)) hoi. hieu ve cac toc va sang tai ((cuc te) OR (cuc thue))".
• Adding a wildcard symbol may retrieve word variants: su xac ky ((nang ma) or (sang tao)) hoi. hieu ve cac toc va sang tai ((cuc te) OR (cuc thue))*.