Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
hieu ve » hieu va
nang xa » nang x, lang xa, nang ma
xa hanh » xa thanh, xa khanh, da hanh
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
va cuu » va cau, va chu, va huu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach y nang xa hoi. ((hieu ve) or (hieu van)) nam thuc ((xa hanh) OR (va hanh)) va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y nang xa hoi. ((hieu ve) OR (hieu van)) nam thuc ((xa hanh) OR (va hanh)) va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach y nang xa hoi. ((hieu ve) or (hieu van)) nam thuc ((xa hanh) OR (va hanh)) va cuu tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach y nang xa hoi. ((hieu ve) or (hieu van)) nam thuc ((xa hanh) OR (va hanh)) va cuu tre*.