Perhaps you should try some spelling variations:
sach tay » xach tay, sach hay, sach nay
tay tang » tay lang, tay trung, tay quang
tu sach » thu sach, su sach, te sach
tang ha » lang ha, tang ma, trung ha
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, xa hoi
luc va » duc va, tuc va
loc va » hoc va
vi cua » vai cua, di cua

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 tay tang ha hoi. ((hieu ve) or (hieu qua)) hau ((luc va) OR (loc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tay tang ha hoi. ((hieu ve) OR (hieu qua)) hau ((luc va) OR (loc va)) hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tay tang ha hoi. ((hieu ve) or (hieu qua)) hau ((luc va) OR (loc va)) hanh vi cua tre*".