Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, tu cach
te sach » toc sach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du
dan vi » doan vi, don vi, dan va
x hoi » xa hoi, o hoi, x ho

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) or (te sach)) ky nang x hoi. hieu ve cac tu va ((dan vi) or (doan va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang x hoi. hieu ve cac tu va ((dan vi) OR (doan va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang x hoi. hieu ve cac tu va ((dan vi) or (doan va)) cua tre*.