Perhaps you should try some spelling variations:
sach vuc » sach duoc, sach nuoc, sach truc
vuc nang » cuc nang, vu nang, chuc nang
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
cam luc » cam xuc, cau luc
co hoi » co hoc, co loi
va cam » va cham, va cac, va cao

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 vuc nang ((cao hoi) OR (co hoi)). hieu va cam luc ((van hanh) or (ban hanh)) ky su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vuc nang ((cao hoi) OR (co hoi)). hieu va cam luc ((van hanh) OR (ban hanh)) ky su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach vuc nang ((cao hoi) OR (co hoi)). hieu va cam luc ((van hanh) or (ban hanh)) ky su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach vuc nang ((cao hoi) OR (co hoi)). hieu va cam luc ((van hanh) or (ban hanh)) ky su triet*.