Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
xuc van » duc van, luc van, xuc ban
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
ve cac » vien cac
o hoi » co hoi, o hoc, o hai

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 ky nang o hoi. hieu ((ve cac) OR (va cac)) xuc van hanh tai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu ((ve cac) OR (va cac)) xuc van hanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu ((ve cac) OR (va cac)) xuc van hanh tai cua tre*.