Perhaps you should try some spelling variations:
tinh tai » trinh tai, tinh thai, tinh hai
tu sach » thu sach, te sach, tu cach
lang xa » lang ha, dang xay, lang van
tai cua » thai cua, tai cuc, tri cua
va tinh » may tinh
qua cac » cua cac
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
su sach » so sach, vu sach
du va » dau va, tu va, su va

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) OR (su sach)) ty ((tang ma) or (lang xa)) hoi. hieu qua cac du va tinh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty ((tang ma) OR (lang xa)) hoi. hieu qua cac du va tinh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ty ((tang ma) or (lang xa)) hoi. hieu qua cac du va tinh tai cua tre*".