Perhaps you should try some spelling variations:
thai thuc » thai thuy, thai tuc, tham thuc
thanh ve » hanh ve, thanh va, thanh vien
thanh vi » hanh vi, thanh va, nhanh vi
toc sach » hoc sach, doc sach, thuoc sach
lang van » dang van, tang van, hoang van
hai tuc » thai tuc, hai cuc, hai huoc
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 tuc) OR (thai thuc)) 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 tuc) OR (thai thuc)) van ((thanh vi) OR (thanh ve)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach _ lang van hoa. hieu qua ((hai tuc) OR (thai thuc)) van ((thanh vi) or (thanh ve)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach _ lang van hoa. hieu qua ((hai tuc) OR (thai thuc)) van ((thanh vi) or (thanh ve)) cua tre*.