Perhaps you should try some spelling variations:
cham luc » cham soc, cham cuu, chat lua
nhan luc » nang luc
hanh tri » thanh tri, hanh tai, hanh trinh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu vu » hieu va, hieu ve, hieu su
va hanh » van hanh, va thanh, va danh
ma hoi » mai hoi, ma hoa, me hoi
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: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu vu ((cham luc) or (nhan luc)) va hanh tri va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu vu ((cham luc) OR (nhan luc)) va hanh tri va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((ma hoi) OR (xa hoi)). hieu vu ((cham luc) or (nhan luc)) va hanh tri va thiet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu vu ((cham luc) or (nhan luc)) va hanh tri va thiet*.