Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
lai hoi » dai hoi, lai hoa, lai roi
cac dai » cac bai, can dai, bac dai
va hanh » van hanh, va thanh, va danh
tu dan » tuc dan, tu ban, cu dan
dan ky » van ky
ma hoi » mai hoi, xa hoi, ma hoa
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 dan ky nang ((ma hoi) or (lai hoi)). hieu van ((cac dai) or (cac dan)) va hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu dan ky nang ((ma hoi) OR (lai hoi)). hieu van ((cac dai) OR (cac dan)) va hanh vi cua vat.
• Adding a wildcard symbol may retrieve word variants: tu dan ky nang ((ma hoi) or (lai hoi)). hieu van ((cac dai) or (cac dan)) va hanh vi cua vat*.