Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
va hanh » va thanh, va danh, ban hanh
cau luc » cau truc, cau phuc
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
tai va » thai va, mai va, tri va
ve cau » ke cau, va cau, ve cac

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

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