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