Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
sach ty » sach y, sach thu, xach tay
hieu va » lieu va, hieu qua
xang xa » lang xa, mang xa, ang xa
sach tu » sach thu, cach tu, sach uu
luu tre » luu tru, cuu tre, luy tre
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) OR (sach tu)) xang xa hoi. hieu va ((nam thuc) OR (dam tu)) van hanh vi luu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) OR (sach tu)) xang xa hoi. hieu va ((nam thuc) or (dam tu)) van hanh vi luu tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) OR (sach tu)) xang xa hoi. hieu va ((nam thuc) or (dam tu)) van hanh vi luu tre*.