Perhaps you should try some spelling variations:
thai cua » than cua, tai cuc, tri cua
anh thai » anh thi, anh tai, nhanh thai
lang van » dang van, tang van, hoang van
qua cac » cua cac
duc ban » duc van, dua ban, duc man
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
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 van)) hoi. hieu qua cac ((duc ban) OR (duc tan)) anh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (lang van)) hoi. hieu qua cac ((duc ban) OR (duc tan)) anh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (lang van)) hoi. hieu qua cac ((duc ban) OR (duc tan)) anh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (lang van)) hoi. hieu qua cac ((duc ban) OR (duc tan)) anh thai cua tre*.