Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
danh vai » danh sai, danh va, doanh van
va danh » va dinh, va dan, va hanh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
ve cac » va cac, vien cac
cac le » cach le, cac he, mac le
le va » le van, te va, ly va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((nang xa) OR (lang xa)) hoi. hieu ve cac le va danh vai ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (lang xa)) hoi. hieu ve cac le va danh vai ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) OR (lang xa)) hoi. hieu ve cac le va danh vai ((cua triet) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) OR (lang xa)) hoi. hieu ve cac le va danh vai ((cua triet) or (va triet))*.