Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
cac toc » cac toi, cac nuoc, cac thoi
cua tre » cua te, cuu tre, cua triet
toc va » hoc va, toc ta, tuc va
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
vi cua » vai cua, di cua

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 (tu sach)) ky nang xa hoi. ((hieu va) or (lieu va)) cac toc va dan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) ky nang xa hoi. ((hieu va) OR (lieu va)) cac toc va dan vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) ky nang xa hoi. ((hieu va) or (lieu va)) cac toc va dan vi cua tre*.