Perhaps you should try some spelling variations:
vao triet » va triet, mao triet, va trien
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
hang di » hang doi, hang vi, hang dien
va hang » van hang, va nang, va lang
cac tuc » cac toc, cac tu, cac tac
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
lang xa » lang ha, lang van
tuc va » thuc va, truc va, tuc xa

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: tu sach y ((lang xa) OR (dang xay)) hoi. ((hieu ve) OR (hieu van)) cac tuc va hang di vao triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((lang xa) OR (dang xay)) hoi. ((hieu ve) or (hieu van)) cac tuc va hang di vao triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((lang xa) OR (dang xay)) hoi. ((hieu ve) or (hieu van)) cac tuc va hang di vao triet*.