Perhaps you should try some spelling variations:
thuat lanh » thuat lap, thuat san
hieu quan » lieu quan, thien quan, lien quan
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dang thi » hoang thi, dang khoi
lanh ky » hanh ky, nganh ky, thanh ky
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
va dang » van dang, va nang, va lang
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 lanh ky lang xa hoi. ((hieu quan) or (hieu qua)) cac nuoc va dang thi ((cua te) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat lanh ky lang xa hoi. ((hieu quan) OR (hieu qua)) cac nuoc va dang thi ((cua te) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: thuat lanh ky lang xa hoi. ((hieu quan) or (hieu qua)) cac nuoc va dang thi ((cua te) or (cua tu))*.