Perhaps you should try some spelling variations:
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
tu sach » thu sach, su sach, tu cach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
te sach » toc sach
cac lo » cac lop, cac co, cac bo
va cua » va chua, via cua, ca cua
ve cac » va cac, vien cac
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 lo ((van hanh) OR (ban hanh)) 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 lo ((van hanh) OR (ban hanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang x hoi. hieu ve cac lo ((van hanh) OR (ban hanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang x hoi. hieu ve cac lo ((van hanh) OR (ban hanh)) va cua tre*.