Perhaps you should try some spelling variations:
ve triet » va trien, su triet
toan ve » toan va, toan ke, toan von
va tinh » may tinh
hieu va » lieu va, hieu qua
hieu ve » hieu van
lang xa » lang ha, dang xay, lang van
sac ky » cac ky, sai ky
cam tu » cam thu, nam tu, dam tu
te sac » te sach, te cac, te san

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

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