Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
nam tuc » nam thuc, nam truc, nam tu
xa hanh » xa thanh, xa khanh, da hanh
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
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: tu sach y nang xa hoi. ((hieu van) or (lieu va)) nam tuc ((xa hanh) OR (va hanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((hieu van) OR (lieu va)) nam tuc ((xa hanh) OR (va hanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. ((hieu van) or (lieu va)) nam tuc ((xa hanh) OR (va hanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. ((hieu van) or (lieu va)) nam tuc ((xa hanh) OR (va hanh)) va cua tre*.