Perhaps you should try some spelling variations:
ban hang » ngan hang
tuc ban » thuc ban, truc ban, tu ban
cac tuc » cac toc, cac tu, cac tac
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ky danh » ky anh
ky dang » ky nang
hai va » hai van, thai va, mai 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: tu sach ((ky dang) or (ky danh)) xa hoi. hieu ve cac tuc ban hang ((hai va) or (hoi 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 ve cac tuc ban hang ((hai va) OR (hoi va)) triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky danh)) xa hoi. hieu ve cac tuc ban hang ((hai va) or (hoi va)) triet*.