Perhaps you should try some spelling variations:
khanh tai » thanh tai, hanh tai, nhanh thai
van khanh » van thanh, van hanh, van anh
sach ky » sac ky, sach ty, sach kem
tai cuu » tai cuc, tai buu, tai cua
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
co hai » co dai, co hoi, o hai
ve cac » va 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) or (sach y)) nang ((o hoi) or (co hai)). hieu ve cac vuc van khanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang ((o hoi) OR (co hai)). hieu ve cac vuc van khanh tai cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang ((o hoi) or (co hai)). hieu ve cac vuc van khanh tai cuu tre*.