Perhaps you should try some spelling variations:
tu sach » thu sach, te sach, tu cach
tinh vi » trinh vi, tinh voi, tinh va
tuc may » truc may, tu may, tuc xay
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
co hoi » co hoc
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky nang ((co hoi) OR (co loi)). hieu va cam tuc may tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang ((co hoi) OR (co loi)). hieu va cam tuc may tinh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang ((co hoi) OR (co loi)). hieu va cam tuc may tinh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang ((co hoi) OR (co loi)). hieu va cam tuc may tinh vi cua tre*.