Perhaps you should try some spelling variations:
manh thai » manh hai, anh thai, manh khai
cac quoc » cac nuoc, cac cuoc, cao quoc
quoc ban » quoc bao, quoc lan, quoc quan
ban manh » ban hanh, van manh, ban mach
thai cua » than cua, tai cuc, tri cua
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
qua cac » cua cac
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 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 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 manh thai cua tre*.