Perhaps you should try some spelling variations:
manh thai » manh hai, anh thai, manh khai
thai cua » than cua, tai cuc, tri cua
quoc bao » quoc oai, hoc bao, quoc va
quoc ban » quoc lan, quoc quan, quoc binh
tu sach » thu sach, su sach, te sach
qua cac » cua cac
sach ty » sach y, sach tu, sach thu
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet

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 ty ((nang xa) or (lang xa)) hoi. hieu qua cac ((quoc ban) OR (quoc bao)) manh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (lang xa)) hoi. hieu qua cac ((quoc ban) OR (quoc bao)) manh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (lang xa)) hoi. hieu qua cac ((quoc ban) OR (quoc bao)) manh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (lang xa)) hoi. hieu qua cac ((quoc ban) OR (quoc bao)) manh thai cua tre*.