Perhaps you should try some spelling variations:
va trinh » van trinh, va tinh, lap trinh
trinh vi » trinh va, trinh ve, trinh viet
thu sai » thu hai, thu tai, thu san
van cac » van cau, van bac, dan cac
van hac » van hoc, van ha, van hai
sai ky » sac ky
ma hoi » mai hoi, xa hoi, me hoi
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: thu sai ky nang ((ma hoi) OR (ma hoa)). hieu ((van cac) or (van hac)) dat va trinh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sai ky nang ((ma hoi) OR (ma hoa)). hieu ((van cac) OR (van hac)) dat va trinh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sai ky nang ((ma hoi) OR (ma hoa)). hieu ((van cac) or (van hac)) dat va trinh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: thu sai ky nang ((ma hoi) OR (ma hoa)). hieu ((van cac) or (van hac)) dat va trinh vi cua vat*.