Perhaps you should try some spelling variations:
thanh voi » thanh loi, thanh moi, hanh voi
dang xay » dang van, van xay
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
cach tu » cach thuc
cac tu » cac thu, cac du, tac tu
voi su » voi suc, oi su, vi su
kien » bien, vien, tien

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((lang xa) or (dang xay)) hoi. hieu va ((cac tu) OR (cach tu)) va thanh voi su kien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((lang xa) OR (dang xay)) hoi. hieu va ((cac tu) OR (cach tu)) va thanh voi su kien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((lang xa) or (dang xay)) hoi. hieu va ((cac tu) OR (cach tu)) va thanh voi su kien".
• Adding a wildcard symbol may retrieve word variants: su sach y ((lang xa) or (dang xay)) hoi. hieu va ((cac tu) OR (cach tu)) va thanh voi su kien*.