Perhaps you should try some spelling variations:
dang xay » dang van, van xay
doanh va » doan va, doanh tai, doanh cua
va doanh » van doanh, vay doanh, va danh
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
van cau » van dau, van hau, van chat
sach ky » sach y, sach ty, sach kem
lang xa » lang ha, lang van
dau tre » dau tren, dau tien, cau tren
sac ky » cac ky, sai ky
va dau » va dao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sac ky)) ((lang xa) OR (dang xay)) hoi. hieu van cau truc va doanh va dau tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) or (sac ky)) ((lang xa) OR (dang xay)) hoi. hieu van cau truc va doanh va dau tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sac ky)) ((lang xa) OR (dang xay)) hoi. hieu van cau truc va doanh va dau tre*.