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