Perhaps you should try some spelling variations:
tieu sach » chieu sach, te sach, viet sach
dien sach » dien anh
anh tang » anh bang, anh dang, anh nang
tang duy » tang du, tang quy, tung duy
duy dung » duc dung, duy hung, duy tung
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((tieu sach) or (dien sach)) - anh tang duy dung ((cong tan) OR (cong san)) van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((tieu sach) OR (dien sach)) - anh tang duy dung ((cong tan) OR (cong san)) van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((tieu sach) or (dien sach)) - anh tang duy dung ((cong tan) OR (cong san)) van ban".
• Adding a wildcard symbol may retrieve word variants: theo ((tieu sach) or (dien sach)) - anh tang duy dung ((cong tan) OR (cong san)) van ban*.