Perhaps you should try some spelling variations:
dam thuc » am thuc, dan thuc, nam thuc
hanh dai » hanh tai, hanh dao, vanh dai
cau tren » cu tren, dau tren, ca tren
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
cam tu » cam thu, nam tu, dam 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 nang x hoi. hieu ve ((dam thuc) or (cam tu)) va hanh dai ((cau tren) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nang x hoi. hieu ve ((dam thuc) OR (cam tu)) va hanh dai ((cau tren) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: te sach tu nang x hoi. hieu ve ((dam thuc) or (cam tu)) va hanh dai ((cau tren) or (cua tre))*.