Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cong cua » cong cu, dong cua, huong cua
phuc ban » phuc van, thuc ban, thuoc ban
van cau » van dau, van hau, van chat
su sach » so sach, vu sach
su sac » su cac, su xac
va cau » va cac, va dau, va cao
nang o » nang co, nang ho, nang ro
cua tu » cua tuc, cua su, cua cu
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) or (su sach)) ky nang o hoi. hieu ((va cau) OR (van cau)) phuc ban thanh cong cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky nang o hoi. hieu ((va cau) OR (van cau)) phuc ban thanh cong cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) or (su sach)) ky nang o hoi. hieu ((va cau) OR (van cau)) phuc ban thanh cong cua tu".
• Adding a wildcard symbol may retrieve word variants: ((su sac) or (su sach)) ky nang o hoi. hieu ((va cau) OR (van cau)) phuc ban thanh cong cua tu*.