Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thu sach » tu sach, thuat sach, thuoc sach
dang xay » dang van, van xay
thanh va » thanh van, hanh va, thanh ha
hieu van » thien van, lieu va, hieu ve
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
cuu tre » cua tre, cau tren, cau treo
cac lo » cac lop, cac co, cac bo
lo ban » co ban, lo van, ly ban
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: thu sach ky ((lang xa) or (dang xay)) hoi. ((hieu van) OR (hieu va)) cac lo ban thanh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((lang xa) OR (dang xay)) hoi. ((hieu van) OR (hieu va)) cac lo ban thanh va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((lang xa) or (dang xay)) hoi. ((hieu van) OR (hieu va)) cac lo ban thanh va cuu tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((lang xa) or (dang xay)) hoi. ((hieu van) OR (hieu va)) cac lo ban thanh va cuu tre*.