Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lang van » dang van, tang van, hoang van
thanh vi » hanh vi, thanh va, nhanh vi
thanh ve » hanh ve, thanh va, thanh vien
qua hai » qua hoat
hai cuc » tai cuc, hai cua, thai cua
cuc van » chuc van, cuu van, cac van
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: toc sach _ lang van hoa. hieu qua hai cuc van ((thanh vi) or (thanh ve)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach _ lang van hoa. hieu qua hai cuc van ((thanh vi) OR (thanh ve)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach _ lang van hoa. hieu qua hai cuc van ((thanh vi) or (thanh ve)) cua tre*.