Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
cac tuc » cac toc, cac tu, cac tac
te sach » toc sach
hieu ve » hieu va, hieu van
ky danh » ky anh
ky dang » ky nang
vai va » mai va, dai va, hai va
ve cac » va cac, vien cac

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

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