Perhaps you should try some spelling variations:
nang duc » nang luc, nang doc, nang du
vu sach » vu bach, su sach, vu khach
vu khac » vu kham, vu khanh, bui khac
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
qua ca » qua cac, qua cua, qua cai
ca tu » ca tru, cau tu, ca thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (vu khac)) ky nang duc loi. hieu qua ca tu ((va danh) OR (va hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khac)) ky nang duc loi. hieu qua ca tu ((va danh) OR (va hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (vu khac)) ky nang duc loi. hieu qua ca tu ((va danh) OR (va hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khac)) ky nang duc loi. hieu qua ca tu ((va danh) OR (va hanh)) vai cua tre*.