Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
su sach » so sach, vu sach
van cau » van dau, van hau, van chat
hanh cu » hanh cua, hanh tu, hanh xu
y nang » ky nang, ly nang, v nang
co hoi » co loi
tuc va » thuc va, truc va, tuc xa
cu va » cuu va, tu va, su va

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 y nang ((co hoi) or (co hoc)). hieu van cau ((duc va) or (tuc va)) hanh cu va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ((co hoi) OR (co hoc)). hieu van cau ((duc va) OR (tuc va)) hanh cu va triet.
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((co hoi) or (co hoc)). hieu van cau ((duc va) or (tuc va)) hanh cu va triet*.