Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
ban hanh » ban hang
dang xay » dang van, van xay
cua tre » cua te, cuu tre, cua triet
san cua » sang cua, ban cua, dan cua
hieu vu » hieu va, hieu ve, hieu su
lang xa » lang ha, lang van
vu cap » vu cao, vu cac
san ky » sang ky, van ky, dan ky
tu san » thu san, tu ban, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky ((lang xa) OR (dang xay)) hoi. hieu vu cap sac ((van thanh) or (ban hanh)) san cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky ((lang xa) OR (dang xay)) hoi. hieu vu cap sac ((van thanh) OR (ban hanh)) san cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky ((lang xa) OR (dang xay)) hoi. hieu vu cap sac ((van thanh) or (ban hanh)) san cua tre".
• Adding a wildcard symbol may retrieve word variants: tu san ky ((lang xa) OR (dang xay)) hoi. hieu vu cap sac ((van thanh) or (ban hanh)) san cua tre*.