Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
cac loc » cac lop, cac hoc, cac nuoc
cac toc » cac toi, cac nuoc, cac thoi
va hanh » van hanh, va thanh, va danh
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky nang x hoi. hieu va ((cac loc) OR (cac toc)) va hanh ((vi cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky nang x hoi. hieu va ((cac loc) OR (cac toc)) va hanh ((vi cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky nang x hoi. hieu va ((cac loc) OR (cac toc)) va hanh ((vi cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu san ky nang x hoi. hieu va ((cac loc) OR (cac toc)) va hanh ((vi cua) or (dai cua)) tre*.