Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
dang xay » dang van, van xay
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tac, cac nuoc
cua tre » cua te, cuu tre, cua triet
cac tu » cac thu, cach tu, cac du

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 ((nang xa) or (dang xay)) hoi. hieu va ((cac tuc) or (cac tu)) va thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (dang xay)) hoi. hieu va ((cac tuc) OR (cac tu)) va thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) or (dang xay)) hoi. hieu va ((cac tuc) or (cac tu)) va thanh dai cua tre*.