Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu san » thuy san, thu ban, phu san
va hanh » van hanh, va thanh, ban hanh
cua tra » ca tra, cua ta, chua tri
va danh » va dinh, va dan, dia danh
nam luc » nang luc, nhan luc, nam thuc
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
san ky » sang ky, van ky, dan ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu san ky tang xa hoi. hieu van nam luc ((va danh) or (va hanh)) di ((cua tra) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu san ky tang xa hoi. hieu van nam luc ((va danh) OR (va hanh)) di ((cua tra) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu san ky tang xa hoi. hieu van nam luc ((va danh) or (va hanh)) di ((cua tra) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: thu san ky tang xa hoi. hieu van nam luc ((va danh) or (va hanh)) di ((cua tra) OR (cua tre))*.