Perhaps you should try some spelling variations:
cham luc » cham soc, nhan luc, cham cuu
qua cham » qua hai, qua cac, va cham
hang tai » hang va, dung tai
hanh tai » thanh tai, han tai, hinh tai
cuu tre » cua tre, cau tren, cau treo
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
su sac » su sach, su cac, su xac
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((x hoi) OR (o hoi)). hieu qua cham luc va ((hanh tai) OR (hang tai)) cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ((x hoi) or (o hoi)). hieu qua cham luc va ((hanh tai) OR (hang tai)) cuu tre~".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ((x hoi) or (o hoi)). hieu qua cham luc va ((hanh tai) OR (hang tai)) cuu tre*.