Perhaps you should try some spelling variations:
dang xay » van xay
dang van » hoang van, hang va
va doanh » van doanh, vay doanh, va danh
nang xa » nang x, lang xa, nang ma
qua bac » qua ban, qua cac, cua bac
bac hoc » bai hoc, bac ho
tai cua » thai cua, tai cuc, tri cua
te sac » te sach, te cac, te san
sac ky » cac ky, sai 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: te sac ky ((nang xa) or (((dang xay) or (dang van)))) hoi. hieu qua bac hoc va doanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (((dang xay) OR (dang van)))) hoi. hieu qua bac hoc va doanh tai cua te.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (((dang xay) or (dang van)))) hoi. hieu qua bac hoc va doanh tai cua te*.