Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tay lang » tai lang, tay tang, tay quang
tu sach » su sach, te sach, tu cach
vai cua » dai cua, hai cua, lai cua
dao vai » dao van, dao va, dao bai
qua cac » cua cac
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, duc 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 (thu sach)) tay lang xa hoi. hieu qua cac ((tuc va) or (tuc xa)) dao vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tay lang xa hoi. hieu qua cac ((tuc va) OR (tuc xa)) dao vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) tay lang xa hoi. hieu qua cac ((tuc va) or (tuc xa)) dao vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) tay lang xa hoi. hieu qua cac ((tuc va) or (tuc xa)) dao vai cua tre*.