Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tang ma » mang may, tang van
hieu ve » hieu van
hieu va » lieu va, hieu qua
dan vai » dan tai, dan vat, den vai
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 7 tang
tro va » tao va, tho va, tro ba
dan va » doan va, dan ca, ban va

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y tang ma hoa. ((hieu ve) OR (hieu va)) cac tro va ((dan vai) OR (dan va)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y tang ma hoa. ((hieu ve) or (hieu va)) cac tro va ((dan vai) OR (dan va)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: thu sach y tang ma hoa. ((hieu ve) or (hieu va)) cac tro va ((dan vai) OR (dan va)) cua tre*.