Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
hieu van » hieu va, thien van, hieu ve
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
tu hang » thu hang, tu hanh, tu hung
cac duc » cac du, cao duc, cac dac
cua tre » cuu tre, cua triet, dua tren
hang x » nang x, hoang xa, chang xu
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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