Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh te » thanh ve, thanh de, thanh le
tu sach » thu sach, su sach, te sach
cam luc » cau luc
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
te cua » tue cua, le cua, de cua

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: tu sach y ((nang ma) OR (nang x)) hoi. hieu va ((cam luc) OR (cam xuc)) ban thanh te cua tre~.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) or (nang x)) hoi. hieu va ((cam luc) or (cam xuc)) ban thanh te cua tre*.