Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dinh dai » dinh dat, sinh dai, dinh dao
van dinh » van minh, van dich, va dinh
hieu cac » hieu luc, hieu va, hieu van
hien cac » thien cac, vien cac, dien cac
sach ky » sac ky, sach y, sach ty
bao van » dao van, cao van, hao van
nang xa » lang xa, nang ma, mang xa
tu sach » thu sach, su sach, te sach

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 ky ((nang xa) OR (nang x)) hoi. hieu ((hien cac) OR (hieu cac)) bao van dinh dai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) OR (nang x)) hoi. hieu ((hien cac) or (hieu cac)) bao van dinh dai cua triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) OR (nang x)) hoi. hieu ((hien cac) or (hieu cac)) bao van dinh dai cua triet*.