Perhaps you should try some spelling variations:
hanh thi » nhanh thi, hanh thoi, anh thi
van hanh » van thanh, ban hanh, van anh
cuoc van » cuoi van, luoc van, quoc van
cac cuoc » cac nuoc, ca cuoc, cac quoc
hieu ve » hieu va, hieu van
thi cua » thai cua, thi cuc, tri cua
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
su hai » su tai
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
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) or (su sach)) y nang ((o hoi) or (su hai)). hieu ve cac cuoc van hanh thi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) y nang ((o hoi) OR (su hai)). hieu ve cac cuoc van hanh thi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) y nang ((o hoi) or (su hai)). hieu ve cac cuoc van hanh thi cua tre*.