Perhaps you should try some spelling variations:
nang doc » nang luc
vu sach » vu bach, su sach, vu khach
va danh » va dinh, va hanh, dia danh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
doc loi » duc loi
vu khac » vu kham, vu khanh, bui khac
cam tu » cam thu, nam tu, dam tu
va dan » ca dan, va dao, va dau
vi cua » vai cua, di cua
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: ((vu sach) or (vu khac)) ky nang doc loi. hieu va cam tu ((va danh) OR (va dan)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khac)) ky nang doc loi. hieu va cam tu ((va danh) OR (va dan)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (vu khac)) ky nang doc loi. hieu va cam tu ((va danh) OR (va dan)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khac)) ky nang doc loi. hieu va cam tu ((va danh) OR (va dan)) vi cua tre*.