Perhaps you should try some spelling variations:
danh dau » hang dau, danh tu, xang dau
thu sac » thu sach, thu san, thu xac
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
cac lo » cac lop, cac co, cac bo
o hai » co hai, so hai, o lai
lo va » lo van, lao va, ly va
o hoi » co hoi, o hoc, o hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang ((o hoi) OR (o hai)). hieu va cac lo va ((danh dau) OR (lanh dao)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang ((o hoi) or (o hai)). hieu va cac lo va ((danh dau) OR (lanh dao)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang ((o hoi) or (o hai)). hieu va cac lo va ((danh dau) OR (lanh dao)) cua tre*.