Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu sach » chieu sach, dien sach, hieu cac
hieu cach » hieu cac, chieu sach, hieu ca
tang van » dang van, hoang van, trong van
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sach) OR (hieu cach)) - anh ((tang van) or (hang va)) thong cong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (hieu cach)) - anh ((tang van) OR (hang va)) thong cong dan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) OR (hieu cach)) - anh ((tang van) or (hang va)) thong cong dan toan ban".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) OR (hieu cach)) - anh ((tang van) or (hang va)) thong cong dan toan ban*.