Perhaps you should try some spelling variations:
te sach » toc sach
dam tuc » dam thuc, dao tuc, nam thuc
hanh di » hanh de, hang di, danh di
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nano xa » nano va, nano bac, nano cau
tu nano » truc nano
dam tu » nam tu, cam tu, tam 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 tu nano xa hoi. hieu va ((dam tuc) or (dam tu)) van ((hanh di) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nano xa hoi. hieu va ((dam tuc) OR (dam tu)) van ((hanh di) OR (hanh vi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach tu nano xa hoi. hieu va ((dam tuc) or (dam tu)) van ((hanh di) or (hanh vi)) cua tre*.