Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
hanh vai » hanh va, hanh tai, hanh van
tac ban » tai ban, cac ban, tao ban
cac tac » cac toc, cac bac, cac dac
te sach » toc sach
ky danh » ky anh
ky dang » ky nang
van cac » van hac, van cau, van bac

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 van cac tac ban ((hanh vai) OR (hanh vi)) 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 van cac tac ban ((hanh vai) OR (hanh vi)) 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 van cac tac ban ((hanh vai) OR (hanh vi)) va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky dang) or (ky danh)) xa hoi. hieu van cac tac ban ((hanh vai) OR (hanh vi)) va triet*.