Perhaps you should try some spelling variations:
thanh tung » thanh cong
hieu sach » chieu sach, hieu cach, hieu cac
dien sach » dien anh
thanh ban » thanh san, thanh van, thanh bac
cong son » cong so, dong son, cong lon
cong san » cong tac
tung va » trung va, tuong va, dung va

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 (dien sach)) - thanh tung va nhung ((cong son) OR (cong san)) thanh ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (dien sach)) - thanh tung va nhung ((cong son) OR (cong san)) thanh ban*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) or (dien sach)) - thanh tung va nhung ((cong son) OR (cong san)) thanh ban*".