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, te sach
lam cua » nam cua, lam chat
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
ve cam » ve cham, ve cac, va cam
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 ty nang x hoi. hieu ((ve cam) or (va cac)) luc ((van hanh) or (ban hanh)) lam cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu ((ve cam) OR (va cac)) luc ((van hanh) OR (ban hanh)) lam cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu ((ve cam) or (va cac)) luc ((van hanh) or (ban hanh)) lam cua tre*.