Perhaps you should try some spelling variations:
danh vai » danh sai, danh va, doanh van
su sach » so sach, vu sach
vu khac » vu kham, vu khanh, bui khac
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
cam tu » cam thu, nam tu, dam tu

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