Perhaps you should try some spelling variations:
va doanh » van doanh, vay doanh, va danh
tham luc » than luc, tham nuoc, tham thuc
dang xay » dang van, van xay
tai cua » thai cua, tai cuc, tri cua
tai cuu » tai cuc, tai buu, thai cua
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
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 (dang xay)) hoi. hieu va tham luc va doanh ((tai cuu) or (tai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((lang xa) OR (dang xay)) hoi. hieu va tham luc va doanh ((tai cuu) OR (tai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((lang xa) OR (dang xay)) hoi. hieu va tham luc va doanh ((tai cuu) or (tai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((lang xa) OR (dang xay)) hoi. hieu va tham luc va doanh ((tai cuu) or (tai cua)) tre*.