Perhaps you should try some spelling variations:
thien van » thi van
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
ban hanh » ban hang
hieu van » hieu va, lieu va, hieu ve
tuc ban » thuc ban, truc ban, tu ban
cac tuc » cac toc, cac tu, cac tac
tu sach » thu sach, su sach, te sach
ky danh » ky anh
ky dang » ky nang
vai va » mai va, dai va, hai 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 ((ky dang) or (ky danh)) xa hoi. ((hieu van) OR (thien van)) cac tuc ban hanh vai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky danh)) xa hoi. ((hieu van) OR (thien van)) cac tuc ban hanh vai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky danh)) xa hoi. ((hieu van) OR (thien van)) cac tuc ban hanh vai va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky danh)) xa hoi. ((hieu van) OR (thien van)) cac tuc ban hanh vai va triet*.