Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
dam tuc » dam thuc, dao tuc, nam thuc
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
luu tre » luu tru, cuu tre, luy tre
lang xa » lang ha, dang xay, lang van
xang xa » mang xa, ang xa, dang xay
dam tu » nam tu, cam tu, tam tu
vi luu » vi lua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((xang xa) OR (lang xa)) hoi. hieu va ((dam tuc) OR (dam tu)) van hanh vi luu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((xang xa) OR (lang xa)) hoi. hieu va ((dam tuc) or (dam tu)) van hanh vi luu tre~".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((xang xa) OR (lang xa)) hoi. hieu va ((dam tuc) or (dam tu)) van hanh vi luu tre*.