Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
viec cac » vien cac, viec cua, viec lam
sach ky » sac ky, sach y, sach ty
vai cau » va cau, van cau, lai chau
vai cac » va cac, tai cac, voi cac
tu sach » thu sach, su sach, te sach
cac co » cac cong
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. hieu viec cac co ((van hanh) or (ban hanh)) ((vai cau) OR (vai cac)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu viec cac co ((van hanh) OR (ban hanh)) ((vai cau) OR (vai cac)) tren*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu viec cac co ((van hanh) or (ban hanh)) ((vai cau) OR (vai cac)) tren*".