Perhaps you should try some spelling variations:
dang xay » dang van, van xay
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cac thoi » cac toi, cac hop, cac tro
tu sach » thu sach, su sach, te sach
dinh te » kinh te, dich te, dinh ve
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
lang ha » long ha
te cua » tue cua, le cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((dang xay) or (lang ha)) hoi. hieu ve ((cac thoi) or (cac nuoc)) va dinh te cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((dang xay) OR (lang ha)) hoi. hieu ve ((cac thoi) OR (cac nuoc)) va dinh te cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((dang xay) or (lang ha)) hoi. hieu ve ((cac thoi) or (cac nuoc)) va dinh te cua tre*.