Perhaps you should try some spelling variations:
thanh trung » thanh tung
phuong dung » thong dung, cuong dung
hieu sach » chieu sach, dien sach, hieu cac
hieu cach » hieu cac, chieu sach, hieu ca
trung cua » truong cua, trung tuan, trung cap
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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)) - thanh trung cua ((phuong dung) or (phuong hoang)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (hieu cach)) - thanh trung cua ((phuong dung) OR (phuong hoang)) dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) OR (hieu cach)) - thanh trung cua ((phuong dung) or (phuong hoang)) dan than cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) OR (hieu cach)) - thanh trung cua ((phuong dung) or (phuong hoang)) dan than cau*.