Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
te sach » toc sach
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
dam tu » nam tu, cam tu, tam tu

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 lang xa hoi. hieu va ((nam thuc) OR (dam tu)) van hanh ((vi luu) OR (vi lua)) tre~.
• Adding a wildcard symbol may retrieve word variants: te sach ty lang xa hoi. hieu va ((nam thuc) or (dam tu)) van hanh ((vi luu) or (vi lua)) tre*.