Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
te sach » toc sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet

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

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