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