Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cac tuc » cac tu, cac tac, cac nuoc
cac toc » cac toi, cac nuoc, cac thoi
cac dac » cac dan, cac dai, cac bac
dau thi » cau thi, dan thi, dao thi
thi cua » thai cua, thi cuc, tri cua
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
va dau » va dao

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 lang xa hoi. hieu va ((((cac tuc) or (cac toc))) or (cac dac)) va dau thi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y lang xa hoi. hieu va ((((cac tuc) OR (cac toc))) OR (cac dac)) va dau thi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y lang xa hoi. hieu va ((((cac tuc) or (cac toc))) or (cac dac)) va dau thi cua tre*.