Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » hieu qua
cau duc » cao duc, cau luc, chu duc
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
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: tu sach y nang xa hoi. ((((hieu ve) or (lieu va))) or (hieu va)) cau duc va dan vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((((hieu ve) OR (lieu va))) OR (hieu va)) cau duc va dan vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. ((((hieu ve) or (lieu va))) or (hieu va)) cau duc va dan vi cua tre*.