Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chiet tach, chieu sang
hieu cach » hieu cac, hieu ca, biet cach
cua khong » cua phuong, cua thuong, cua cong
hua khong » hoa khong, hoac khong, phuc khong
thong anh » thong danh, thong lanh, hong anh
tuan cu » tuan tu, quan cua, tuan thu

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