Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
hang hai » hoang hai, hang tai, thanh hai
co sach » bo sach, cuon sach, hoc sach
qua cac » cua cac
truc va » thuc va, thuc vat, trung va
va hang » van hang, va nang, va lang
y nang » ky nang, ly nang, v nang
co hai » co dai, co hoi, so hai
hai su » hai vu, lai su, hai so
o hoi » co hoi, o hoc, o hoa
o hai » so hai, o lai, _ hai
kien » bien, vien, tien

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

• Performing a fuzzy search may retrieve terms with similar spellings: co sach y nang ((o hoi) or (((o hai) or (co hai)))). hieu qua cac truc va hang hai su kien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach y nang ((o hoi) OR (((o hai) OR (co hai)))). hieu qua cac truc va hang hai su kien.
• Adding a wildcard symbol may retrieve word variants: co sach y nang ((o hoi) or (((o hai) or (co hai)))). hieu qua cac truc va hang hai su kien*.