Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh dai » thanh tai, thanh dat, thanh oai
hieu van » hieu va, thien van, lieu va
te sach » toc sach
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
hang x » hoang xa, chang xu, hang nxb

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 ty ((hang x) OR (nang x)) hoi. hieu van cac duc va ((thanh dai) or (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((hang x) OR (nang x)) hoi. hieu van cac duc va ((thanh dai) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((hang x) OR (nang x)) hoi. hieu van cac duc va ((thanh dai) or (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((hang x) OR (nang x)) hoi. hieu van cac duc va ((thanh dai) or (thanh hai)) cua tre*.