Perhaps you should try some spelling variations:
tan thanh » tran thanh, tang thanh, toan thanh
thanh di » thanh doi, thanh de, thanh do
cua viet » ca viet, cua vat, cua dieu
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
cac duc » cao duc, cac dac, cac nuoc
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky

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 lang xa hoi. hieu qua ((cac duc) OR (cac du)) tan thanh di ((cua viet) or (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky lang xa hoi. hieu qua ((cac duc) OR (cac du)) tan thanh di ((cua viet) OR (hoa viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky lang xa hoi. hieu qua ((cac duc) OR (cac du)) tan thanh di ((cua viet) or (hoa viet))".
• Adding a wildcard symbol may retrieve word variants: tu san ky lang xa hoi. hieu qua ((cac duc) OR (cac du)) tan thanh di ((cua viet) or (hoa viet))*.