Perhaps you should try some spelling variations:
thuat san » thuat toan, thuat song, thuat lanh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dang thi » hoang thi, dang khoi
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va dang » van dang, va nang, va lang
san ky » sang ky, van ky, dan ky
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat san ky ((nang xa) OR (lang xa)) hoi. hieu va cac nuoc va dang thi ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat san ky ((nang xa) OR (lang xa)) hoi. hieu va cac nuoc va dang thi ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat san ky ((nang xa) OR (lang xa)) hoi. hieu va cac nuoc va dang thi ((cua te) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: thuat san ky ((nang xa) OR (lang xa)) hoi. hieu va cac nuoc va dang thi ((cua te) or (cua tu))*.