Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
dam thuc » am thuc, dan thuc, nam thuc
te sach » toc sach
dai cuu » dai cua, dai huu
va hanh » van hanh, va thanh, va danh
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
hang ma » hang ca, tang ma, nang ma
cuu tre » cua tre, cau tren, cau treo
cam tu » cam thu, nam tu, dam tu

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 ma) OR (hang va)) hoi. hieu ve ((dam thuc) or (cam tu)) va hanh dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((hang ma) OR (hang va)) hoi. hieu ve ((dam thuc) OR (cam tu)) va hanh dai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((hang ma) OR (hang va)) hoi. hieu ve ((dam thuc) or (cam tu)) va hanh dai cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((hang ma) OR (hang va)) hoi. hieu ve ((dam thuc) or (cam tu)) va hanh dai cuu tre*.