Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, tu cach
te sach » toc sach
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
cac tac » cac toc, cac bac, cac dac
van mat » van dat, van man, van mao
mat cuu » mat cua
cuu tre » cua tre, cau tren, cau treo
tac va » tac da, tac xa, tuc va

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) OR (te sach)) ky nang xa hoi. ((hieu va) or (lieu va)) cac tac va van mat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang xa hoi. ((hieu va) OR (lieu va)) cac tac va van mat cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky nang xa hoi. ((hieu va) or (lieu va)) cac tac va van mat cuu tre*".