Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
cham vuc » cham soc, pham duc, cham cuu
van nhan » van phan, van thanh, danh nhan
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
van han » van hanh, van phan, van hoan
tai va » thai va, mai va, tri va
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ((x hoi) or (o hoi)). hieu qua cham vuc ((van han) or (van nhan)) tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((x hoi) OR (o hoi)). hieu qua cham vuc ((van han) OR (van nhan)) tai va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((x hoi) or (o hoi)). hieu qua cham vuc ((van han) or (van nhan)) tai va thiet*.