Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua viet » hoa viet, cua vat, cua dieu
thanh de » hanh de, thanh ve, thanh do
ca viet » va viet, co viet, hoa viet
lang xa » lang ha, dang xay, lang van
vuc ban » vu ban, duc ban, cuc ban
san ky » sang ky, van ky, ban ky
dan ky » van ky
qua ca » qua cac, qua cua, qua cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((san ky) or (dan ky)) lang xa hoi. hieu qua ca vuc ban thanh de ((cua viet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((san ky) OR (dan ky)) lang xa hoi. hieu qua ca vuc ban thanh de ((cua viet) OR (ca viet)).
• Adding a wildcard symbol may retrieve word variants: tu ((san ky) or (dan ky)) lang xa hoi. hieu qua ca vuc ban thanh de ((cua viet) or (ca viet))*.