Perhaps you should try some spelling variations:
sach tham » sach nha
sach thue » sach thu, sach thieu, cach thuc
thai cua » than cua, tai cuc, tri cua
da thai » dao thai, do thai, ca thai
cac tuc » cac toc, cac tu, cac tac
cua tre » cua te, cuu tre, cua triet
qua cac » cua cac
van hoi » van hoc, van hoe, van loi
tuc va » thuc va, truc va, tuc xa
va da » va dao, va dau, va dap

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach thue) or (sach tham)) lang ((van hoi) OR (van hoa)). hieu qua cac tuc va da thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thue) OR (sach tham)) lang ((van hoi) OR (van hoa)). hieu qua cac tuc va da thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thue) or (sach tham)) lang ((van hoi) OR (van hoa)). hieu qua cac tuc va da thai cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach thue) or (sach tham)) lang ((van hoi) OR (van hoa)). hieu qua cac tuc va da thai cua tre*.