Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
dan soc » dan toc, dan hoc, dan so
lang xa » dang xay, lang van
cuu tre » cua tre, cau tren, cau treo
lang ha » long ha
va hanh » van hanh, va thanh, va danh
soc va » hoc va, loc va, doc va
ke san » ke dan
va dan » ca dan, va dao, va dau
san ky » sang ky, van ky, dan ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ke san ky ((lang xa) OR (lang ha)) hoi. hieu va dan soc va hanh vi ((cuu tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ke san ky ((lang xa) OR (lang ha)) hoi. hieu va dan soc va hanh vi ((cuu tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "ke san ky ((lang xa) OR (lang ha)) hoi. hieu va dan soc va hanh vi ((cuu tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: ke san ky ((lang xa) OR (lang ha)) hoi. hieu va dan soc va hanh vi ((cuu tre) or (cua te))*.