Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu sach » chieu sach, hieu cach, hieu cac
dien sach » dien anh
tranh cua » doanh cua
dan chinh » dang chinh, lan chinh, van chinh
chinh can » chinh ca, chinh ban, chinh cau
manh cua » doanh cua, ban cua
cong dan » cong san, cong tan, huong dan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (dien sach)) - canh ((tranh cua) OR (manh cua)) thong cong dan chinh can~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) or (dien sach)) - canh ((tranh cua) OR (manh cua)) thong cong dan chinh can~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) or (dien sach)) - canh ((tranh cua) OR (manh cua)) thong cong dan chinh can*.