Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh hai » thanh hai, nhanh hai, hang hai
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
hieu ve » hieu va, hieu van
xuc van » duc van, luc van, vuc van
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
o hoi » co hoi, o hoc, o hoa
o hai » co hai, so hai, o lai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu nang ((o hoi) or (o hai)). hieu ve cam xuc van hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nang ((o hoi) OR (o hai)). hieu ve cam xuc van hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach tu nang ((o hoi) or (o hai)). hieu ve cam xuc van hanh hai cua tre*.