Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sac » thu sach, thu san, thu xac
cao hoi » cau hoi, cao hoc, tao hoi
cac dat » cai dat, cac dai, cac dac
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
sac ky » cac ky, sai ky
co hoi » co hoc, co loi
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky nang ((cao hoi) OR (co hoi)). hieu van ((cac dat) or (cac dan)) va tinh va cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang ((cao hoi) OR (co hoi)). hieu van ((cac dat) OR (cac dan)) va tinh va cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang ((cao hoi) OR (co hoi)). hieu van ((cac dat) or (cac dan)) va tinh va cua vat".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang ((cao hoi) OR (co hoi)). hieu van ((cac dat) or (cac dan)) va tinh va cua vat*.