Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
dang xay » dang van
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
co sach » bo sach, cuon sach, hoc sach
sach ky » sac ky, sach y, sach ty
qua hai » qua hoat
hai tuc » thai tuc, hai cuc, thai thuc
tuc van » thuc van, truc van, tuc va

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: co sach ky ((dang xay) OR (van xay)) hoi. hieu qua hai tuc van hanh vi ((cua triet) OR (va triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ky ((dang xay) OR (van xay)) hoi. hieu qua hai tuc van hanh vi ((cua triet) or (va triet))~".
• Adding a wildcard symbol may retrieve word variants: co sach ky ((dang xay) OR (van xay)) hoi. hieu qua hai tuc van hanh vi ((cua triet) or (va triet))*.