Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
doanh van » doan van, doanh va, doanh ban
danh vai » danh sai, danh va, dang van
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cac duc » cac du, cao duc, cac dac
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
van cac » van hac, van cau, van bac

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 (lang xa)) hoi. hieu van cac duc va ((danh vai) OR (doanh van)) cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (lang xa)) hoi. hieu van cac duc va ((danh vai) OR (doanh van)) cua triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (lang xa)) hoi. hieu van cac duc va ((danh vai) OR (doanh van)) cua triet*.