Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
van cac » van hac, van cau, van bac
cac tac » cac toc, cac bac, cac dac
va hanh » va thanh, va danh, ban hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
su cao » cu cao, vu cao, su co
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: ((su sac) or (su cao)) ky nang x hoi. hieu van cac tac ((va hanh) OR (van hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su cao)) ky nang x hoi. hieu van cac tac ((va hanh) OR (van hanh)) vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) or (su cao)) ky nang x hoi. hieu van cac tac ((va hanh) OR (van hanh)) vai cua tre*".