Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu sach » chieu sach, hieu cach, dien sach
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, thanh va
trinh va » trinh van, trinh vat, trinh ve
cong dan » cong san, cong tan, huong dan
dan phan » doan phan, dan chan, van phan
phan cau » phan dau, phan cac, phan tu

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 - canh ((tranh va) or (trinh va)) thong cong dan phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - canh ((tranh va) OR (trinh va)) thong cong dan phan cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - canh ((tranh va) or (trinh va)) thong cong dan phan cau*.